ubuntu-cve-2026-43617
Vulnerability from osv_ubuntu
Published
2026-05-20 00:00
Modified
2026-06-16 11:30
Summary
Details

Rsync version 3.4.2 and prior contain an authorization bypass vulnerability in the rsync daemon's hostname-based access control list enforcement when configured with chroot. Attackers can bypass hostname-based deny rules by controlling the PTR record for their source IP address, allowing connections from hostnames that administrators intended to deny when reverse DNS resolution fails and defaults to UNKNOWN.

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

{
  "affected": [
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "rsync",
            "binary_version": "3.1.0-2ubuntu0.4+esm3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:14.04:LTS",
        "name": "rsync",
        "purl": "pkg:deb/ubuntu/rsync@3.1.0-2ubuntu0.4+esm3?arch=source\u0026distro=esm-infra-legacy/trusty"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.1.0-2ubuntu0.4+esm3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.0.9-4ubuntu1",
        "3.1.0-2",
        "3.1.0-2ubuntu0.1",
        "3.1.0-2ubuntu0.2",
        "3.1.0-2ubuntu0.3",
        "3.1.0-2ubuntu0.4",
        "3.1.0-2ubuntu0.4+esm1",
        "3.1.0-2ubuntu0.4+esm2"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "rsync",
            "binary_version": "3.1.1-3ubuntu1.3+esm5"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "rsync",
        "purl": "pkg:deb/ubuntu/rsync@3.1.1-3ubuntu1.3+esm5?arch=source\u0026distro=esm-infra-legacy/xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.1.1-3ubuntu1.3+esm5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.1.1-3",
        "3.1.1-3ubuntu1",
        "3.1.1-3ubuntu1.1",
        "3.1.1-3ubuntu1.2",
        "3.1.1-3ubuntu1.3",
        "3.1.1-3ubuntu1.3+esm1",
        "3.1.1-3ubuntu1.3+esm2",
        "3.1.1-3ubuntu1.3+esm3",
        "3.1.1-3ubuntu1.3+esm4"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "rsync",
            "binary_version": "3.1.2-2.1ubuntu1.6+esm3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:18.04:LTS",
        "name": "rsync",
        "purl": "pkg:deb/ubuntu/rsync@3.1.2-2.1ubuntu1.6+esm3?arch=source\u0026distro=esm-infra/bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.1.2-2.1ubuntu1.6+esm3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.1.2-2",
        "3.1.2-2.1",
        "3.1.2-2.1ubuntu1",
        "3.1.2-2.1ubuntu1.1",
        "3.1.2-2.1ubuntu1.2",
        "3.1.2-2.1ubuntu1.3",
        "3.1.2-2.1ubuntu1.4",
        "3.1.2-2.1ubuntu1.5",
        "3.1.2-2.1ubuntu1.6",
        "3.1.2-2.1ubuntu1.6+esm1",
        "3.1.2-2.1ubuntu1.6+esm2"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "rsync",
            "binary_version": "3.1.3-8ubuntu0.9+esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:20.04:LTS",
        "name": "rsync",
        "purl": "pkg:deb/ubuntu/rsync@3.1.3-8ubuntu0.9+esm1?arch=source\u0026distro=esm-infra/focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.1.3-8ubuntu0.9+esm1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.1.3-6",
        "3.1.3-8",
        "3.1.3-8ubuntu0.1",
        "3.1.3-8ubuntu0.2",
        "3.1.3-8ubuntu0.3",
        "3.1.3-8ubuntu0.4",
        "3.1.3-8ubuntu0.5",
        "3.1.3-8ubuntu0.7",
        "3.1.3-8ubuntu0.8",
        "3.1.3-8ubuntu0.9"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "rsync",
            "binary_version": "3.2.7-0ubuntu0.22.04.6"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "rsync",
        "purl": "pkg:deb/ubuntu/rsync@3.2.7-0ubuntu0.22.04.6?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.2.7-0ubuntu0.22.04.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.2.3-4ubuntu1",
        "3.2.3-4ubuntu2",
        "3.2.3-8ubuntu1",
        "3.2.3-8ubuntu2",
        "3.2.3-8ubuntu3",
        "3.2.3-8ubuntu3.1",
        "3.2.7-0ubuntu0.22.04.2",
        "3.2.7-0ubuntu0.22.04.3",
        "3.2.7-0ubuntu0.22.04.4"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "rsync",
            "binary_version": "3.2.7-1ubuntu1.4"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "rsync",
        "purl": "pkg:deb/ubuntu/rsync@3.2.7-1ubuntu1.4?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.2.7-1ubuntu1.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.2.7-1",
        "3.2.7-1build1",
        "3.2.7-1build2",
        "3.2.7-1ubuntu1",
        "3.2.7-1ubuntu1.1",
        "3.2.7-1ubuntu1.2"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "rsync",
            "binary_version": "3.4.1+ds1-5ubuntu1.2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "rsync",
        "purl": "pkg:deb/ubuntu/rsync@3.4.1+ds1-5ubuntu1.2?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.4.1+ds1-5ubuntu1.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.4.1+ds1-3",
        "3.4.1+ds1-4",
        "3.4.1+ds1-5",
        "3.4.1+ds1-5ubuntu1"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "rsync",
            "binary_version": "3.4.1+ds1-7ubuntu0.2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "rsync",
        "purl": "pkg:deb/ubuntu/rsync@3.4.1+ds1-7ubuntu0.2?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.4.1+ds1-7ubuntu0.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.4.1+ds1-5ubuntu1",
        "3.4.1+ds1-6",
        "3.4.1+ds1-7"
      ]
    }
  ],
  "aliases": [],
  "details": "Rsync version\u00a03.4.2 and prior contain an authorization bypass vulnerability in the rsync daemon\u0027s hostname-based access control list enforcement when configured with chroot. Attackers can bypass hostname-based deny rules by controlling the PTR record for their source IP address, allowing connections from hostnames that administrators intended to deny when reverse DNS resolution fails and defaults to UNKNOWN.",
  "id": "UBUNTU-CVE-2026-43617",
  "modified": "2026-06-16T11:30:16Z",
  "published": "2026-05-20T00:00:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-43617"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-43617"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/RsyncProject/rsync/security/advisories/GHSA-rjfm-3w2m-jf4f"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8283-1"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8349-1"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8349-2"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8349-3"
    }
  ],
  "related": [
    "USN-8283-1",
    "USN-8349-1",
    "USN-8349-2",
    "USN-8349-3"
  ],
  "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:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-43617"
  ]
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





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.
  • 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.


Detection rules are retrieved from Rulezet.