USN-8907-1 (UBUNTU-CVE-2026-53583)

Vulnerability from osv_ubuntu – Published: 2026-10-08 13:40 – Updated: 2026-10-08 13:40 – Source website
VLAI
Summary
libgit2 vulnerability
Details

It was discovered that libgit2 incorrectly handled IP address SubjectAltName verification in TLS certificate validation. A remote attacker with a CA-trusted certificate could possibly use this issue to perform a machine-in-the-middle attack, leading to the exposure of sensitive information.

References
To clipboard 

{
  "affected": [
    {
      "database_specific": {
        "cves_map": {
          "cves": [
            {
              "id": "CVE-2026-53583",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            }
          ],
          "ecosystem": "Ubuntu:24.04:LTS"
        }
      },
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "libgit2-1.7",
            "binary_version": "1.7.2+ds-1ubuntu3.3"
          },
          {
            "binary_name": "libgit2-fixtures",
            "binary_version": "1.7.2+ds-1ubuntu3.3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "libgit2",
        "purl": "pkg:deb/ubuntu/libgit2@1.7.2+ds-1ubuntu3.3?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.7.2+ds-1ubuntu3.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.5.1+ds-1ubuntu1",
        "1.7.1+ds-2ubuntu1",
        "1.7.2+ds-1ubuntu1",
        "1.7.2+ds-1ubuntu2",
        "1.7.2+ds-1ubuntu3",
        "1.7.2+ds-1ubuntu3.1",
        "1.7.2+ds-1ubuntu3.2"
      ]
    },
    {
      "database_specific": {
        "cves_map": {
          "cves": [
            {
              "id": "CVE-2026-53583",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            }
          ],
          "ecosystem": "Ubuntu:26.04:LTS"
        }
      },
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "libgit2-1.9",
            "binary_version": "1.9.1+ds-1ubuntu1.3"
          },
          {
            "binary_name": "libgit2-fixtures",
            "binary_version": "1.9.1+ds-1ubuntu1.3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "libgit2",
        "purl": "pkg:deb/ubuntu/libgit2@1.9.1+ds-1ubuntu1.3?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.9.1+ds-1ubuntu1.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.9.0+ds-2ubuntu2",
        "1.9.1+ds-1ubuntu1",
        "1.9.1+ds-1ubuntu1.1",
        "1.9.1+ds-1ubuntu1.2"
      ]
    }
  ],
  "aliases": [],
  "details": "It was discovered that libgit2 incorrectly handled IP address\nSubjectAltName verification in TLS certificate validation. A remote\nattacker with a CA-trusted certificate could possibly use this issue\nto perform a machine-in-the-middle attack, leading to the exposure\nof sensitive information.",
  "id": "USN-8907-1",
  "modified": "2026-10-08T13:40:27Z",
  "published": "2026-10-08T13:40:27Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8907-1"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-53583"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "summary": "libgit2 vulnerability",
  "upstream": [
    "UBUNTU-CVE-2026-53583"
  ]
}



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.



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.