UBUNTU-CVE-2026-3731 (CVE-2026-3731)

Vulnerability from osv_ubuntu – Published: 2026-03-08 11:15 – Updated: 2026-09-11 12:34 – Source website
VLAI
Details

A weakness has been identified in libssh up to 0.11.3. The impacted element is the function sftp_extensions_get_name/sftp_extensions_get_data of the file src/sftp.c of the component SFTP Extension Name Handler. Executing a manipulation of the argument idx can lead to out-of-bounds read. The attack may be performed from remote. Upgrading to version 0.11.4 and 0.12.0 is sufficient to resolve this issue. This patch is called 855a0853ad3abd4a6cd85ce06fce6d8d4c7a0b60. You should upgrade the affected component.

Severity
5.3 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
6.9 (Medium)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
N/A (UNKNOWN)
medium
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libssh-4",
            "binary_version": "0.6.3-4.3ubuntu0.6+esm5"
          },
          {
            "binary_name": "libssh-gcrypt-4",
            "binary_version": "0.6.3-4.3ubuntu0.6+esm5"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "libssh",
        "purl": "pkg:deb/ubuntu/libssh@0.6.3-4.3ubuntu0.6+esm5?arch=source\u0026distro=esm-infra/xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.6.3-4.3ubuntu0.6+esm5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.6.3-3ubuntu3",
        "0.6.3-4.1",
        "0.6.3-4.2",
        "0.6.3-4.2ubuntu1",
        "0.6.3-4.3",
        "0.6.3-4.3ubuntu0.1",
        "0.6.3-4.3ubuntu0.2",
        "0.6.3-4.3ubuntu0.5",
        "0.6.3-4.3ubuntu0.6",
        "0.6.3-4.3ubuntu0.6+esm1",
        "0.6.3-4.3ubuntu0.6+esm2",
        "0.6.3-4.3ubuntu0.6+esm3",
        "0.6.3-4.3ubuntu0.6+esm4"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libssh-4",
            "binary_version": "0.8.0~20170825.94fa1e38-1ubuntu0.7+esm7"
          },
          {
            "binary_name": "libssh-gcrypt-4",
            "binary_version": "0.8.0~20170825.94fa1e38-1ubuntu0.7+esm7"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:18.04:LTS",
        "name": "libssh",
        "purl": "pkg:deb/ubuntu/libssh@0.8.0~20170825.94fa1e38-1ubuntu0.7+esm7?arch=source\u0026distro=esm-infra/bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.8.0~20170825.94fa1e38-1ubuntu0.7+esm7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.7.5-1",
        "0.8.0~20170825.94fa1e38-1",
        "0.8.0~20170825.94fa1e38-1build1",
        "0.8.0~20170825.94fa1e38-1ubuntu0.1",
        "0.8.0~20170825.94fa1e38-1ubuntu0.2",
        "0.8.0~20170825.94fa1e38-1ubuntu0.5",
        "0.8.0~20170825.94fa1e38-1ubuntu0.6",
        "0.8.0~20170825.94fa1e38-1ubuntu0.7",
        "0.8.0~20170825.94fa1e38-1ubuntu0.7+esm3",
        "0.8.0~20170825.94fa1e38-1ubuntu0.7+esm4",
        "0.8.0~20170825.94fa1e38-1ubuntu0.7+esm5",
        "0.8.0~20170825.94fa1e38-1ubuntu0.7+esm6"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libssh-4",
            "binary_version": "0.9.3-2ubuntu2.5+esm4"
          },
          {
            "binary_name": "libssh-gcrypt-4",
            "binary_version": "0.9.3-2ubuntu2.5+esm4"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:20.04:LTS",
        "name": "libssh",
        "purl": "pkg:deb/ubuntu/libssh@0.9.3-2ubuntu2.5+esm4?arch=source\u0026distro=esm-infra/focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.9.3-2ubuntu2.5+esm4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.9.0-1ubuntu1",
        "0.9.0-1ubuntu4",
        "0.9.0-1ubuntu5",
        "0.9.3-2ubuntu1",
        "0.9.3-2ubuntu2",
        "0.9.3-2ubuntu2.1",
        "0.9.3-2ubuntu2.2",
        "0.9.3-2ubuntu2.3",
        "0.9.3-2ubuntu2.4",
        "0.9.3-2ubuntu2.5",
        "0.9.3-2ubuntu2.5+esm1",
        "0.9.3-2ubuntu2.5+esm2",
        "0.9.3-2ubuntu2.5+esm3"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "libssh-4",
            "binary_version": "0.9.6-2ubuntu0.22.04.7"
          },
          {
            "binary_name": "libssh-gcrypt-4",
            "binary_version": "0.9.6-2ubuntu0.22.04.7"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "libssh",
        "purl": "pkg:deb/ubuntu/libssh@0.9.6-2ubuntu0.22.04.7?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.9.6-2ubuntu0.22.04.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.9.6-1",
        "0.9.6-1build1",
        "0.9.6-2",
        "0.9.6-2build1",
        "0.9.6-2ubuntu0.22.04.1",
        "0.9.6-2ubuntu0.22.04.2",
        "0.9.6-2ubuntu0.22.04.3",
        "0.9.6-2ubuntu0.22.04.4",
        "0.9.6-2ubuntu0.22.04.5",
        "0.9.6-2ubuntu0.22.04.6"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "libssh-4",
            "binary_version": "0.10.6-2ubuntu0.4"
          },
          {
            "binary_name": "libssh-gcrypt-4",
            "binary_version": "0.10.6-2ubuntu0.4"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "libssh",
        "purl": "pkg:deb/ubuntu/libssh@0.10.6-2ubuntu0.4?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.10.6-2ubuntu0.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.10.5-3ubuntu1",
        "0.10.5-3ubuntu2",
        "0.10.6-2",
        "0.10.6-2build1",
        "0.10.6-2build2",
        "0.10.6-2ubuntu0.1",
        "0.10.6-2ubuntu0.2",
        "0.10.6-2ubuntu0.3"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "libssh-4",
            "binary_version": "0.11.2-1ubuntu0.3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "libssh",
        "purl": "pkg:deb/ubuntu/libssh@0.11.2-1ubuntu0.3?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.11.2-1ubuntu0.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.11.1-1",
        "0.11.1-2",
        "0.11.2-1",
        "0.11.2-1build1",
        "0.11.2-1ubuntu0.1",
        "0.11.2-1ubuntu0.2"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "libssh-4",
            "binary_version": "0.11.3-1ubuntu2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "libssh",
        "purl": "pkg:deb/ubuntu/libssh@0.11.3-1ubuntu2?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.11.3-1ubuntu2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.11.2-1build1",
        "0.11.3-1",
        "0.11.3-1ubuntu1"
      ]
    }
  ],
  "aliases": [],
  "details": "A weakness has been identified in libssh up to 0.11.3. The impacted element is the function sftp_extensions_get_name/sftp_extensions_get_data of the file src/sftp.c of the component SFTP Extension Name Handler. Executing a manipulation of the argument idx can lead to out-of-bounds read. The attack may be performed from remote. Upgrading to version 0.11.4 and 0.12.0 is sufficient to resolve this issue. This patch is called 855a0853ad3abd4a6cd85ce06fce6d8d4c7a0b60. You should upgrade the affected component.",
  "id": "UBUNTU-CVE-2026-3731",
  "modified": "2026-09-11T12:34:54Z",
  "published": "2026-03-08T11:15:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-3731"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-3731"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8093-1"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8093-2"
    }
  ],
  "related": [
    "USN-8093-1",
    "USN-8093-2"
  ],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
      "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:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-3731"
  ]
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.
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  • 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.



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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.