Vulnerability-Lookup

USN-8799-1 (UBUNTU-CVE-2026-58050)

Vulnerability from osv_ubuntu – Published: 2026-09-22 03:58 – Updated: 2026-09-23 04:27 – Source website

Summary

libssh2 vulnerabilities

Details

It was discovered that libssh2 incorrectly handled certain publickey subsystem attributes. A remote attacker controlling a malicious SSH server could use this issue to cause a denial of service or possibly execute arbitrary code. (CVE-2026-58050)

It was discovered that libssh2 did not properly initialize publickey list entries before parsing. A remote attacker controlling a malicious SSH server could use this issue to cause a denial of service or possibly execute arbitrary code. (CVE-2026-58051)

It was discovered that libssh2 incorrectly handled certain SFTP server responses. A remote attacker controlling an SSH server could use this issue to cause libssh2 to crash or possibly execute arbitrary code. (CVE-2026-66032)

It was discovered that libssh2 did not properly check bounds in certain publickey subsystem responses. A remote attacker controlling a malicious SSH server could use this issue to cause a denial of service or possibly execute arbitrary code.. (CVE-2026-66034)

References

URL

Type

	https://ubuntu.com/security/notices/USN-8799-1	ADVISORY
	https://ubuntu.com/security/CVE-2026-58050	REPORT
	https://ubuntu.com/security/CVE-2026-58051	REPORT
	https://ubuntu.com/security/CVE-2026-66032	REPORT
	https://ubuntu.com/security/CVE-2026-66034	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "database_specific": {
        "cves_map": {
          "cves": [
            {
              "id": "CVE-2026-58050",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-58051",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-66032",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-66034",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            }
          ],
          "ecosystem": "Ubuntu:Pro:14.04:LTS"
        }
      },
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libssh2-1",
            "binary_version": "1.4.3-2ubuntu0.2+esm4"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:14.04:LTS",
        "name": "libssh2",
        "purl": "pkg:deb/ubuntu/libssh2@1.4.3-2ubuntu0.2+esm4?arch=source\u0026distro=esm-infra-legacy/trusty"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.4.3-2ubuntu0.2+esm4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.4.3-1",
        "1.4.3-2",
        "1.4.3-2ubuntu0.1",
        "1.4.3-2ubuntu0.2",
        "1.4.3-2ubuntu0.2+esm1",
        "1.4.3-2ubuntu0.2+esm2",
        "1.4.3-2ubuntu0.2+esm3"
      ]
    },
    {
      "database_specific": {
        "cves_map": {
          "cves": [
            {
              "id": "CVE-2026-58050",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-58051",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-66032",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-66034",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            }
          ],
          "ecosystem": "Ubuntu:Pro:16.04:LTS"
        }
      },
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libssh2-1",
            "binary_version": "1.5.0-2ubuntu0.1+esm3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "libssh2",
        "purl": "pkg:deb/ubuntu/libssh2@1.5.0-2ubuntu0.1+esm3?arch=source\u0026distro=esm-apps-legacy/xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.5.0-2ubuntu0.1+esm3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.5.0-2",
        "1.5.0-2ubuntu0.1",
        "1.5.0-2ubuntu0.1+esm1",
        "1.5.0-2ubuntu0.1+esm2"
      ]
    },
    {
      "database_specific": {
        "cves_map": {
          "cves": [
            {
              "id": "CVE-2026-58050",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-58051",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-66032",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-66034",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            }
          ],
          "ecosystem": "Ubuntu:Pro:18.04:LTS"
        }
      },
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libssh2-1",
            "binary_version": "1.8.0-1ubuntu0.1+esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:18.04:LTS",
        "name": "libssh2",
        "purl": "pkg:deb/ubuntu/libssh2@1.8.0-1ubuntu0.1+esm1?arch=source\u0026distro=esm-apps/bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.8.0-1ubuntu0.1+esm1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.8.0-1",
        "1.8.0-1ubuntu0.1"
      ]
    },
    {
      "database_specific": {
        "cves_map": {
          "cves": [
            {
              "id": "CVE-2026-58050",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-58051",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-66032",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-66034",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            }
          ],
          "ecosystem": "Ubuntu:Pro:20.04:LTS"
        }
      },
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libssh2-1",
            "binary_version": "1.8.0-2.1ubuntu0.1+esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:20.04:LTS",
        "name": "libssh2",
        "purl": "pkg:deb/ubuntu/libssh2@1.8.0-2.1ubuntu0.1+esm1?arch=source\u0026distro=esm-apps/focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.8.0-2.1ubuntu0.1+esm1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.8.0-2.1build1",
        "1.8.0-2.1ubuntu0.1"
      ]
    },
    {
      "database_specific": {
        "cves_map": {
          "cves": [
            {
              "id": "CVE-2026-58050",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-58051",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-66032",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-66034",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            }
          ],
          "ecosystem": "Ubuntu:22.04:LTS"
        }
      },
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "libssh2-1",
            "binary_version": "1.10.0-3ubuntu0.1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "libssh2",
        "purl": "pkg:deb/ubuntu/libssh2@1.10.0-3ubuntu0.1?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.10.0-3ubuntu0.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.9.0-3",
        "1.10.0-2",
        "1.10.0-2build1",
        "1.10.0-3"
      ]
    }
  ],
  "aliases": [],
  "details": "It was discovered that libssh2 incorrectly handled certain publickey\nsubsystem attributes. A remote attacker controlling a malicious SSH server\ncould use this issue to cause a denial of service or possibly execute\narbitrary code.\n(CVE-2026-58050)\n\nIt was discovered that libssh2 did not properly initialize publickey list\nentries before parsing. A remote attacker controlling a malicious SSH\nserver could use this issue to cause a denial of service or possibly\nexecute arbitrary code. (CVE-2026-58051)\n\nIt was discovered that libssh2 incorrectly handled certain SFTP server\nresponses. A remote attacker controlling an SSH server could use this issue\nto cause libssh2 to crash or possibly execute arbitrary code.\n(CVE-2026-66032)\n\nIt was discovered that libssh2 did not properly check bounds in certain \npublickey subsystem responses. A remote attacker controlling a malicious \nSSH server could use this issue to cause a denial of service or possibly \nexecute arbitrary code.. (CVE-2026-66034)",
  "id": "USN-8799-1",
  "modified": "2026-09-23T04:27:57Z",
  "published": "2026-09-22T03:58:05Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8799-1"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-58050"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-58051"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-66032"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-66034"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "summary": "libssh2 vulnerabilities",
  "upstream": [
    "UBUNTU-CVE-2026-58050",
    "UBUNTU-CVE-2026-58051",
    "UBUNTU-CVE-2026-66032",
    "UBUNTU-CVE-2026-66034"
  ]
}

UBUNTU-CVE-2026-58050 (CVE-2026-58050)

Vulnerability from osv_ubuntu – Published: 2026-06-28 02:16 – Updated: 2026-09-23 04:59 – Source website

Details

libssh2 through 1.11.1 reads an attacker-controlled 32-bit attribute count from a publickey-subsystem response and uses it in the allocation num_attrs * sizeof(libssh2_publickey_attribute) without bounds checking, so on 32-bit platforms the multiplication overflows to an undersized buffer. A malicious SSH server can then drive the attribute-parsing loop to write past the allocation, causing a heap buffer overflow in a connecting libssh2 client.

Severity

7.0 (High)


                    
                      CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H

7.5 (High)


                    
                      CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

8.3 (High)


                    
                      CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2026-58050	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-58050	REPORT
	https://github.com/bikini/exploitarium/tree/main/…	REPORT
	https://github.com/libssh2/libssh2/blob/master/sr…	REPORT
	https://www.vulncheck.com/advisories/libssh2-inte…	REPORT
	https://github.com/libssh2/libssh2/pull/2205#disc…	REPORT
	https://ubuntu.com/security/notices/USN-8532-1	ADVISORY
	https://ubuntu.com/security/notices/USN-8799-1	ADVISORY

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libssh2-1",
            "binary_version": "1.4.3-2ubuntu0.2+esm4"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:14.04:LTS",
        "name": "libssh2",
        "purl": "pkg:deb/ubuntu/libssh2@1.4.3-2ubuntu0.2+esm4?arch=source\u0026distro=esm-infra-legacy/trusty"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.4.3-2ubuntu0.2+esm4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.4.3-1",
        "1.4.3-2",
        "1.4.3-2ubuntu0.1",
        "1.4.3-2ubuntu0.2",
        "1.4.3-2ubuntu0.2+esm1",
        "1.4.3-2ubuntu0.2+esm2",
        "1.4.3-2ubuntu0.2+esm3"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libssh2-1",
            "binary_version": "1.5.0-2ubuntu0.1+esm3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "libssh2",
        "purl": "pkg:deb/ubuntu/libssh2@1.5.0-2ubuntu0.1+esm3?arch=source\u0026distro=esm-apps-legacy/xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.5.0-2ubuntu0.1+esm3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.5.0-2",
        "1.5.0-2ubuntu0.1",
        "1.5.0-2ubuntu0.1+esm1",
        "1.5.0-2ubuntu0.1+esm2"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libssh2-1",
            "binary_version": "1.8.0-1ubuntu0.1+esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:18.04:LTS",
        "name": "libssh2",
        "purl": "pkg:deb/ubuntu/libssh2@1.8.0-1ubuntu0.1+esm1?arch=source\u0026distro=esm-apps/bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.8.0-1ubuntu0.1+esm1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.8.0-1",
        "1.8.0-1ubuntu0.1"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libssh2-1",
            "binary_version": "1.8.0-2.1ubuntu0.1+esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:20.04:LTS",
        "name": "libssh2",
        "purl": "pkg:deb/ubuntu/libssh2@1.8.0-2.1ubuntu0.1+esm1?arch=source\u0026distro=esm-apps/focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.8.0-2.1ubuntu0.1+esm1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.8.0-2.1build1",
        "1.8.0-2.1ubuntu0.1"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "libssh2-1",
            "binary_version": "1.10.0-3ubuntu0.1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "libssh2",
        "purl": "pkg:deb/ubuntu/libssh2@1.10.0-3ubuntu0.1?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.10.0-3ubuntu0.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.9.0-3",
        "1.10.0-2",
        "1.10.0-2build1",
        "1.10.0-3"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "libssh2-1t64",
            "binary_version": "1.11.0-4.1ubuntu0.24.04.3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "libssh2",
        "purl": "pkg:deb/ubuntu/libssh2@1.11.0-4.1ubuntu0.24.04.3?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.11.0-4.1ubuntu0.24.04.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.11.0-2",
        "1.11.0-3",
        "1.11.0-4",
        "1.11.0-4.1build1",
        "1.11.0-4.1build2",
        "1.11.0-4.1ubuntu0.24.04.1",
        "1.11.0-4.1ubuntu0.24.04.2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libssh2-1t64",
            "binary_version": "1.11.1-1ubuntu0.25.10.2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "libssh2",
        "purl": "pkg:deb/ubuntu/libssh2@1.11.1-1ubuntu0.25.10.2?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.11.1-1",
        "1.11.1-1build1",
        "1.11.1-1ubuntu0.25.10.1",
        "1.11.1-1ubuntu0.25.10.2"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "libssh2-1t64",
            "binary_version": "1.11.1-1ubuntu0.26.04.3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "libssh2",
        "purl": "pkg:deb/ubuntu/libssh2@1.11.1-1ubuntu0.26.04.3?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.11.1-1ubuntu0.26.04.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.11.1-1build1",
        "1.11.1-1build2",
        "1.11.1-1ubuntu0.26.04.1",
        "1.11.1-1ubuntu0.26.04.2"
      ]
    }
  ],
  "aliases": [],
  "details": "libssh2 through 1.11.1 reads an attacker-controlled 32-bit attribute count from a publickey-subsystem response and uses it in the allocation num_attrs * sizeof(libssh2_publickey_attribute) without bounds checking, so on 32-bit platforms the multiplication overflows to an undersized buffer. A malicious SSH server can then drive the attribute-parsing loop to write past the allocation, causing a heap buffer overflow in a connecting libssh2 client.",
  "id": "UBUNTU-CVE-2026-58050",
  "modified": "2026-09-23T04:59:08Z",
  "published": "2026-06-28T02:16:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-58050"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-58050"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/bikini/exploitarium/tree/main/libssh2-publickey-list-calc-poc"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/libssh2/libssh2/blob/master/src/publickey.c"
    },
    {
      "type": "REPORT",
      "url": "https://www.vulncheck.com/advisories/libssh2-integer-overflow-in-publickey-subsystem-attribute-allocation"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/libssh2/libssh2/pull/2205#discussion_r3523193089"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8532-1"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8799-1"
    }
  ],
  "related": [
    "USN-8532-1",
    "USN-8799-1"
  ],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-58050"
  ]
}

UBUNTU-CVE-2026-58051 (CVE-2026-58051)

Vulnerability from osv_ubuntu – Published: 2026-06-28 02:16 – Updated: 2026-09-23 04:59 – Source website

Details

libssh2 through 1.11.1 grows its publickey list with SSH2_REALLOC but does not zero-initialize new entries before parsing populates them, so a parse failure reaching the cleanup path leaves libssh2_publickey_list_free operating on an uninitialized entry. A malicious SSH server offering the publickey subsystem can use a malformed response to make cleanup free an uninitialized, attacker-influenceable attrs pointer in a connecting libssh2 client.

Severity

6.5 (Medium)


                    
                      CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H

8.3 (High)


                    
                      CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2026-58051	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-58051	REPORT
	https://github.com/bikini/exploitarium/tree/main/…	REPORT
	https://github.com/libssh2/libssh2/blob/master/sr…	REPORT
	https://www.vulncheck.com/advisories/libssh2-free…	REPORT
	https://github.com/libssh2/libssh2/pull/2202	REPORT
	https://ubuntu.com/security/notices/USN-8532-1	ADVISORY
	https://ubuntu.com/security/notices/USN-8799-1	ADVISORY

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libssh2-1",
            "binary_version": "1.4.3-2ubuntu0.2+esm4"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:14.04:LTS",
        "name": "libssh2",
        "purl": "pkg:deb/ubuntu/libssh2@1.4.3-2ubuntu0.2+esm4?arch=source\u0026distro=esm-infra-legacy/trusty"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.4.3-2ubuntu0.2+esm4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.4.3-1",
        "1.4.3-2",
        "1.4.3-2ubuntu0.1",
        "1.4.3-2ubuntu0.2",
        "1.4.3-2ubuntu0.2+esm1",
        "1.4.3-2ubuntu0.2+esm2",
        "1.4.3-2ubuntu0.2+esm3"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libssh2-1",
            "binary_version": "1.5.0-2ubuntu0.1+esm3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "libssh2",
        "purl": "pkg:deb/ubuntu/libssh2@1.5.0-2ubuntu0.1+esm3?arch=source\u0026distro=esm-apps-legacy/xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.5.0-2ubuntu0.1+esm3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.5.0-2",
        "1.5.0-2ubuntu0.1",
        "1.5.0-2ubuntu0.1+esm1",
        "1.5.0-2ubuntu0.1+esm2"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libssh2-1",
            "binary_version": "1.8.0-1ubuntu0.1+esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:18.04:LTS",
        "name": "libssh2",
        "purl": "pkg:deb/ubuntu/libssh2@1.8.0-1ubuntu0.1+esm1?arch=source\u0026distro=esm-apps/bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.8.0-1ubuntu0.1+esm1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.8.0-1",
        "1.8.0-1ubuntu0.1"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libssh2-1",
            "binary_version": "1.8.0-2.1ubuntu0.1+esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:20.04:LTS",
        "name": "libssh2",
        "purl": "pkg:deb/ubuntu/libssh2@1.8.0-2.1ubuntu0.1+esm1?arch=source\u0026distro=esm-apps/focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.8.0-2.1ubuntu0.1+esm1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.8.0-2.1build1",
        "1.8.0-2.1ubuntu0.1"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "libssh2-1",
            "binary_version": "1.10.0-3ubuntu0.1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "libssh2",
        "purl": "pkg:deb/ubuntu/libssh2@1.10.0-3ubuntu0.1?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.10.0-3ubuntu0.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.9.0-3",
        "1.10.0-2",
        "1.10.0-2build1",
        "1.10.0-3"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "libssh2-1t64",
            "binary_version": "1.11.0-4.1ubuntu0.24.04.3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "libssh2",
        "purl": "pkg:deb/ubuntu/libssh2@1.11.0-4.1ubuntu0.24.04.3?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.11.0-4.1ubuntu0.24.04.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.11.0-2",
        "1.11.0-3",
        "1.11.0-4",
        "1.11.0-4.1build1",
        "1.11.0-4.1build2",
        "1.11.0-4.1ubuntu0.24.04.1",
        "1.11.0-4.1ubuntu0.24.04.2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libssh2-1t64",
            "binary_version": "1.11.1-1ubuntu0.25.10.2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "libssh2",
        "purl": "pkg:deb/ubuntu/libssh2@1.11.1-1ubuntu0.25.10.2?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.11.1-1",
        "1.11.1-1build1",
        "1.11.1-1ubuntu0.25.10.1",
        "1.11.1-1ubuntu0.25.10.2"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "libssh2-1t64",
            "binary_version": "1.11.1-1ubuntu0.26.04.3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "libssh2",
        "purl": "pkg:deb/ubuntu/libssh2@1.11.1-1ubuntu0.26.04.3?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.11.1-1ubuntu0.26.04.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.11.1-1build1",
        "1.11.1-1build2",
        "1.11.1-1ubuntu0.26.04.1",
        "1.11.1-1ubuntu0.26.04.2"
      ]
    }
  ],
  "aliases": [],
  "details": "libssh2 through 1.11.1 grows its publickey list with SSH2_REALLOC but does not zero-initialize new entries before parsing populates them, so a parse failure reaching the cleanup path leaves libssh2_publickey_list_free operating on an uninitialized entry. A malicious SSH server offering the publickey subsystem can use a malformed response to make cleanup free an uninitialized, attacker-influenceable attrs pointer in a connecting libssh2 client.",
  "id": "UBUNTU-CVE-2026-58051",
  "modified": "2026-09-23T04:59:08Z",
  "published": "2026-06-28T02:16:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-58051"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-58051"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/bikini/exploitarium/tree/main/libssh2-publickey-list-calc-poc"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/libssh2/libssh2/blob/master/src/publickey.c"
    },
    {
      "type": "REPORT",
      "url": "https://www.vulncheck.com/advisories/libssh2-free-of-uninitialized-pointer-in-publickey-list-cleanup"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/libssh2/libssh2/pull/2202"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8532-1"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8799-1"
    }
  ],
  "related": [
    "USN-8532-1",
    "USN-8799-1"
  ],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-58051"
  ]
}

UBUNTU-CVE-2026-66032 (CVE-2026-66032)

Vulnerability from osv_ubuntu – Published: 2026-07-24 17:17 – Updated: 2026-09-23 05:00 – Source website

Details

libssh2 through 1.11.1, fixed in commit 5e47761, contains a double-free vulnerability in the sftp_open() function in src/sftp.c that allows a malicious SSH server to corrupt the heap of any authenticated client opening an SFTP session. When a server responds to SSH_FXP_OPEN with SSH_FXP_STATUS containing FX_OK, the response data buffer is freed, and if a subsequent sftp_packet_require() call returns a specific error such as LIBSSH2_ERROR_CHANNEL_PACKET_EXCEEDED, the same pointer is freed a second time, enabling tcache dup conditions on glibc systems that allow overlapping allocations and function pointer overwrites.

Severity

8.8 (High)


                    
                      CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

8.7 (High)


                    
                      CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2026-66032	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-66032	REPORT
	https://github.com/libssh2/libssh2/pull/2180	REPORT
	https://www.vulncheck.com/advisories/libssh2-doub…	REPORT
	https://ubuntu.com/security/notices/USN-8722-1	ADVISORY
	https://ubuntu.com/security/notices/USN-8799-1	ADVISORY

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libssh2-1",
            "binary_version": "1.4.3-2ubuntu0.2+esm4"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:14.04:LTS",
        "name": "libssh2",
        "purl": "pkg:deb/ubuntu/libssh2@1.4.3-2ubuntu0.2+esm4?arch=source\u0026distro=esm-infra-legacy/trusty"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.4.3-2ubuntu0.2+esm4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.4.3-1",
        "1.4.3-2",
        "1.4.3-2ubuntu0.1",
        "1.4.3-2ubuntu0.2",
        "1.4.3-2ubuntu0.2+esm1",
        "1.4.3-2ubuntu0.2+esm2",
        "1.4.3-2ubuntu0.2+esm3"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libssh2-1",
            "binary_version": "1.5.0-2ubuntu0.1+esm3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "libssh2",
        "purl": "pkg:deb/ubuntu/libssh2@1.5.0-2ubuntu0.1+esm3?arch=source\u0026distro=esm-apps-legacy/xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.5.0-2ubuntu0.1+esm3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.5.0-2",
        "1.5.0-2ubuntu0.1",
        "1.5.0-2ubuntu0.1+esm1",
        "1.5.0-2ubuntu0.1+esm2"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libssh2-1",
            "binary_version": "1.8.0-1ubuntu0.1+esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:18.04:LTS",
        "name": "libssh2",
        "purl": "pkg:deb/ubuntu/libssh2@1.8.0-1ubuntu0.1+esm1?arch=source\u0026distro=esm-apps/bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.8.0-1ubuntu0.1+esm1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.8.0-1",
        "1.8.0-1ubuntu0.1"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libssh2-1",
            "binary_version": "1.8.0-2.1ubuntu0.1+esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:20.04:LTS",
        "name": "libssh2",
        "purl": "pkg:deb/ubuntu/libssh2@1.8.0-2.1ubuntu0.1+esm1?arch=source\u0026distro=esm-apps/focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.8.0-2.1ubuntu0.1+esm1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.8.0-2.1build1",
        "1.8.0-2.1ubuntu0.1"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "libssh2-1",
            "binary_version": "1.10.0-3ubuntu0.1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "libssh2",
        "purl": "pkg:deb/ubuntu/libssh2@1.10.0-3ubuntu0.1?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.10.0-3ubuntu0.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.9.0-3",
        "1.10.0-2",
        "1.10.0-2build1",
        "1.10.0-3"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "libssh2-1t64",
            "binary_version": "1.11.0-4.1ubuntu0.24.04.4"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "libssh2",
        "purl": "pkg:deb/ubuntu/libssh2@1.11.0-4.1ubuntu0.24.04.4?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.11.0-4.1ubuntu0.24.04.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.11.0-2",
        "1.11.0-3",
        "1.11.0-4",
        "1.11.0-4.1build1",
        "1.11.0-4.1build2",
        "1.11.0-4.1ubuntu0.24.04.1",
        "1.11.0-4.1ubuntu0.24.04.2",
        "1.11.0-4.1ubuntu0.24.04.3"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "libssh2-1t64",
            "binary_version": "1.11.1-1ubuntu0.26.04.4"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "libssh2",
        "purl": "pkg:deb/ubuntu/libssh2@1.11.1-1ubuntu0.26.04.4?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.11.1-1ubuntu0.26.04.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.11.1-1build1",
        "1.11.1-1build2",
        "1.11.1-1ubuntu0.26.04.1",
        "1.11.1-1ubuntu0.26.04.2",
        "1.11.1-1ubuntu0.26.04.3"
      ]
    }
  ],
  "aliases": [],
  "details": "libssh2 through 1.11.1, fixed in commit 5e47761, contains a double-free vulnerability in the sftp_open() function in src/sftp.c that allows a malicious SSH server to corrupt the heap of any authenticated client opening an SFTP session. When a server responds to SSH_FXP_OPEN with SSH_FXP_STATUS containing FX_OK, the response data buffer is freed, and if a subsequent sftp_packet_require() call returns a specific error such as LIBSSH2_ERROR_CHANNEL_PACKET_EXCEEDED, the same pointer is freed a second time, enabling tcache dup conditions on glibc systems that allow overlapping allocations and function pointer overwrites.",
  "id": "UBUNTU-CVE-2026-66032",
  "modified": "2026-09-23T05:00:46Z",
  "published": "2026-07-24T17:17:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-66032"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-66032"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/libssh2/libssh2/pull/2180"
    },
    {
      "type": "REPORT",
      "url": "https://www.vulncheck.com/advisories/libssh2-double-free-heap-corruption-via-sftp-open"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8722-1"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8799-1"
    }
  ],
  "related": [
    "USN-8722-1",
    "USN-8799-1"
  ],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-66032"
  ]
}

UBUNTU-CVE-2026-66034 (CVE-2026-66034)

Vulnerability from osv_ubuntu – Published: 2026-07-24 17:17 – Updated: 2026-09-23 05:00 – Source website

Details

libssh2 through 1.11.1, fixed in commit a13bb6c, contains a missing bounds check vulnerability that allows a malicious SSH server to trigger an arbitrary-length heap out-of-bounds read and a free of an uninitialized pointer via the publickey subsystem. In libssh2_publickey_list_fetch(), the version 1 response parser reads a server-controlled comment_len value and advances the parse pointer without verifying sufficient bytes remain in the buffer, causing the out-of-bounds read to leak heap pointers from adjacent allocations defeating ASLR, followed by heap allocator state corruption when the error cleanup path frees an uninitialized pointer from a non-zeroed realloc() region.

Severity

7.5 (High)


                    
                      CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

7.7 (High)


                    
                      CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2026-66034	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-66034	REPORT
	https://github.com/libssh2/libssh2/pull/2202	REPORT
	https://www.vulncheck.com/advisories/libssh2-heap…	REPORT
	https://ubuntu.com/security/notices/USN-8799-1	ADVISORY

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libssh2-1",
            "binary_version": "1.4.3-2ubuntu0.2+esm4"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:14.04:LTS",
        "name": "libssh2",
        "purl": "pkg:deb/ubuntu/libssh2@1.4.3-2ubuntu0.2+esm4?arch=source\u0026distro=esm-infra-legacy/trusty"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.4.3-2ubuntu0.2+esm4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.4.3-1",
        "1.4.3-2",
        "1.4.3-2ubuntu0.1",
        "1.4.3-2ubuntu0.2",
        "1.4.3-2ubuntu0.2+esm1",
        "1.4.3-2ubuntu0.2+esm2",
        "1.4.3-2ubuntu0.2+esm3"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libssh2-1",
            "binary_version": "1.5.0-2ubuntu0.1+esm3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "libssh2",
        "purl": "pkg:deb/ubuntu/libssh2@1.5.0-2ubuntu0.1+esm3?arch=source\u0026distro=esm-apps-legacy/xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.5.0-2ubuntu0.1+esm3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.5.0-2",
        "1.5.0-2ubuntu0.1",
        "1.5.0-2ubuntu0.1+esm1",
        "1.5.0-2ubuntu0.1+esm2"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libssh2-1",
            "binary_version": "1.8.0-1ubuntu0.1+esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:18.04:LTS",
        "name": "libssh2",
        "purl": "pkg:deb/ubuntu/libssh2@1.8.0-1ubuntu0.1+esm1?arch=source\u0026distro=esm-apps/bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.8.0-1ubuntu0.1+esm1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.8.0-1",
        "1.8.0-1ubuntu0.1"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libssh2-1",
            "binary_version": "1.8.0-2.1ubuntu0.1+esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:20.04:LTS",
        "name": "libssh2",
        "purl": "pkg:deb/ubuntu/libssh2@1.8.0-2.1ubuntu0.1+esm1?arch=source\u0026distro=esm-apps/focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.8.0-2.1ubuntu0.1+esm1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.8.0-2.1build1",
        "1.8.0-2.1ubuntu0.1"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "libssh2-1",
            "binary_version": "1.10.0-3ubuntu0.1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "libssh2",
        "purl": "pkg:deb/ubuntu/libssh2@1.10.0-3ubuntu0.1?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.10.0-3ubuntu0.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.9.0-3",
        "1.10.0-2",
        "1.10.0-2build1",
        "1.10.0-3"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "libssh2-1t64",
            "binary_version": "1.11.0-4.1ubuntu0.24.04.3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "libssh2",
        "purl": "pkg:deb/ubuntu/libssh2@1.11.0-4.1ubuntu0.24.04.3?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.11.0-4.1ubuntu0.24.04.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.11.0-2",
        "1.11.0-3",
        "1.11.0-4",
        "1.11.0-4.1build1",
        "1.11.0-4.1build2",
        "1.11.0-4.1ubuntu0.24.04.1",
        "1.11.0-4.1ubuntu0.24.04.2"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "libssh2-1t64",
            "binary_version": "1.11.1-1ubuntu0.26.04.3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "libssh2",
        "purl": "pkg:deb/ubuntu/libssh2@1.11.1-1ubuntu0.26.04.3?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.11.1-1ubuntu0.26.04.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.11.1-1build1",
        "1.11.1-1build2",
        "1.11.1-1ubuntu0.26.04.1",
        "1.11.1-1ubuntu0.26.04.2"
      ]
    }
  ],
  "aliases": [],
  "details": "libssh2 through 1.11.1, fixed in commit a13bb6c, contains a missing bounds check vulnerability that allows a malicious SSH server to trigger an arbitrary-length heap out-of-bounds read and a free of an uninitialized pointer via the publickey subsystem. In libssh2_publickey_list_fetch(), the version 1 response parser reads a server-controlled comment_len value and advances the parse pointer without verifying sufficient bytes remain in the buffer, causing the out-of-bounds read to leak heap pointers from adjacent allocations defeating ASLR, followed by heap allocator state corruption when the error cleanup path frees an uninitialized pointer from a non-zeroed realloc() region.",
  "id": "UBUNTU-CVE-2026-66034",
  "modified": "2026-09-23T05:00:46Z",
  "published": "2026-07-24T17:17:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-66034"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-66034"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/libssh2/libssh2/pull/2202"
    },
    {
      "type": "REPORT",
      "url": "https://www.vulncheck.com/advisories/libssh2-heap-out-of-bounds-read-via-publickey-subsystem"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8799-1"
    }
  ],
  "related": [
    "USN-8799-1"
  ],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-66034"
  ]
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

USN-8799-1 (UBUNTU-CVE-2026-58050)

UBUNTU-CVE-2026-58050 (CVE-2026-58050)

UBUNTU-CVE-2026-58051 (CVE-2026-58051)

UBUNTU-CVE-2026-66032 (CVE-2026-66032)

UBUNTU-CVE-2026-66034 (CVE-2026-66034)

Tags

Sightings

Nomenclature

Related by attack behaviour