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cosign — security advisory

Type: advisorySources: OSVAdvisory ID: UBUNTU-CVE-2026-24122

Cosign provides code signing and transparency for containers and binaries. In versions 3.0.4 and below, an issuing certificate with a validity that expires before the leaf certificate will be considered valid during verification even if the provided timestamp would mean the issuing certificate should be considered expired. When verifying artifact signatures using a certificate, Cosign first verifies the certificate chain using the leaf certificate's "not before" timestamp and later checks expiry of the leaf certificate using either a signed timestamp provided by the Rekor transparency log or from a timestamp authority, or using the current time. The root and all issuing certificates are assumed to be valid during the leaf certificate's validity. There is no impact to users of the public Sigstore infrastructure. This may affect private deployments with customized PKIs. This issue has been fixed in version 3.0.5.

Products
cosign
Affected versions
2.4.3-1, 2.5.0-2, 2.5.0-2build1, 2.6.2-1, 2.6.2-1ubuntu0.26.04.1~esm1, 3.1.1-1
Fixed versions
Not specified
CVEs
CVE-2026-24122
Confirmed fixed CVEs
Not specified
Updated in this feed
31 Oct 2026, 02:58 UTC · Revision 1

Source evidence

UBUNTU-CVE-2026-24122

core-osv · Original source

Published 19 Feb 2026, 23:16 UTC

Cosign provides code signing and transparency for containers and binaries. In versions 3.0.4 and below, an issuing certificate with a validity that expires before the leaf certificate will be considered valid during verification even if the provided timestamp would mean the issuing certificate should be considered expired. When verifying artifact signatures using a certificate, Cosign first verifies the certificate chain using the leaf certificate's "not before" timestamp and later checks expiry of the leaf certificate using either a signed timestamp provided by the Rekor transparency log or from a timestamp authority, or using the current time. The root and all issuing certificates are assumed to be valid during the leaf certificate's validity. There is no impact to users of the public Sigstore infrastructure. This may affect private deployments with customized PKIs. This issue has been fixed in version 3.0.5.

osv:UBUNTU-CVE-2026-24122

cosign

Fixed versions: Not specified

cosign

Fixed versions: Not specified

cosign

Fixed versions: Not specified

Complete source record
{
  "id": "36c7409b40afb650d1d1aa61f39648f37d7ebf0e5850bc412ead9efcd18c8e19",
  "url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-24122",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "UBUNTU-CVE-2026-24122",
    "summary": "Cosign provides code signing and transparency for containers and binaries. In versions 3.0.4 and below, an issuing certificate with a validity that expires before the leaf certificate will be considered valid during verification even if the provided timestamp would mean the issuing certificate should be considered expired. When verifying artifact signatures using a certificate, Cosign first verifies the certificate chain using the leaf certificate's \"not before\" timestamp and later checks expiry of the leaf certificate using either a signed timestamp provided by the Rekor transparency log or from a timestamp authority, or using the current time. The root and all issuing certificates are assumed to be valid during the leaf certificate's validity. There is no impact to users of the public Sigstore infrastructure. This may affect private deployments with customized PKIs. This issue has been fixed in version 3.0.5.",
    "evidence": "osv:UBUNTU-CVE-2026-24122",
    "products": [
      {
        "name": {
          "value": "cosign",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "2.4.3-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2.5.0-2",
            "evidence": "/affected/0/versions"
          }
        ]
      },
      {
        "name": {
          "value": "cosign",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "2.6.2-1",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "3.1.1-1",
            "evidence": "/affected/1/versions"
          }
        ]
      },
      {
        "name": {
          "value": "cosign",
          "evidence": "/affected/2/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "2.5.0-2",
            "evidence": "/affected/2/versions"
          },
          {
            "value": "2.5.0-2build1",
            "evidence": "/affected/2/versions"
          },
          {
            "value": "2.6.2-1",
            "evidence": "/affected/2/versions"
          },
          {
            "value": "2.6.2-1ubuntu0.26.04.1~esm1",
            "evidence": "/affected/2/versions"
          }
        ]
      }
    ],
    "severity": "low",
    "structured": {
      "id": "UBUNTU-CVE-2026-24122",
      "aliases": [
        "UBUNTU-CVE-2026-24122"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N"
        },
        {
          "type": "Ubuntu",
          "score": "medium"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "cosign",
            "purl": "pkg:deb/ubuntu/cosign?arch=source&distro=questing",
            "ecosystem": "Ubuntu:25.10"
          },
          "versions": [
            "2.4.3-1",
            "2.5.0-2"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-24122.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "cosign",
                "binary_version": "2.5.0-2"
              },
              {
                "binary_name": "golang-github-sigstore-cosign-dev",
                "binary_version": "2.5.0-2"
              }
            ]
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "cosign",
            "purl": "pkg:deb/ubuntu/cosign?arch=source&distro=stonking",
            "ecosystem": "Ubuntu:26.10"
          },
          "versions": [
            "2.6.2-1",
            "3.1.1-1"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-24122.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "cosign",
                "binary_version": "3.1.1-1"
              },
              {
                "binary_name": "golang-github-sigstore-cosign-dev",
                "binary_version": "3.1.1-1"
              }
            ]
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "cosign",
            "purl": "pkg:deb/ubuntu/cosign?arch=source&distro=esm-apps%2Fresolute",
            "ecosystem": "Ubuntu:Pro:26.04:LTS"
          },
          "versions": [
            "2.5.0-2",
            "2.5.0-2build1",
            "2.6.2-1",
            "2.6.2-1ubuntu0.26.04.1~esm1"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-24122.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "cosign",
                "binary_version": "2.6.2-1ubuntu0.26.04.1~esm1"
              },
              {
                "binary_name": "golang-github-sigstore-cosign-dev",
                "binary_version": "2.6.2-1ubuntu0.26.04.1~esm1"
              }
            ]
          }
        }
      ],
      "modified": "2026-10-17T12:59:56.856199119Z",
      "provider": "osv",
      "upstream": [
        "CVE-2026-24122"
      ],
      "references": [
        "https://ubuntu.com/security/CVE-2026-24122",
        "https://www.cve.org/CVERecord?id=CVE-2026-24122",
        "https://github.com/sigstore/cosign/commit/3c9a7363f563db76d78e2de2cabd945450f3781e",
        "https://github.com/sigstore/cosign/releases/tag/v3.0.5",
        "https://github.com/sigstore/cosign/security/advisories/GHSA-wfqv-66vq-46rm"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2026-24122",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 360021,
  "published_at": "2026-02-19T23:16:00+00:00"
}