sigstore-go — security advisory

{
  "id": "c1759374112465ac5e1ec55788bf0616d20ba7ece2b0e2e470d1f824b9ea5b82",
  "url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-54787",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "UBUNTU-CVE-2026-54787",
    "summary": "sigstore-go is a Go library for Sigstore signing and verification. Prior to 1.2.1, sigstore-go does not check a bundle signing timestamp against the validity window of an ExpiringKey wrapping a self-managed long-lived signing key without a certificate, which can allow an attacker holding expired key material to sign accepted bundles. This issue is fixed in version 1.2.1.",
    "evidence": "osv:UBUNTU-CVE-2026-54787",
    "products": [
      {
        "name": {
          "value": "sigstore-go",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "1.1.4-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.3.0-1",
            "evidence": "/affected/0/versions"
          }
        ]
      },
      {
        "name": {
          "value": "sigstore-go",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "0.7.1-2",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "0.7.3-1",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "0.7.3-2",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "1.1.4-1",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "1.1.4-1ubuntu0.26.04.1~esm1",
            "evidence": "/affected/1/versions"
          }
        ]
      }
    ],
    "severity": "low",
    "structured": {
      "id": "UBUNTU-CVE-2026-54787",
      "aliases": [
        "UBUNTU-CVE-2026-54787"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N"
        },
        {
          "type": "Ubuntu",
          "score": "medium"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "sigstore-go",
            "purl": "pkg:deb/ubuntu/sigstore-go?arch=source&distro=stonking",
            "ecosystem": "Ubuntu:26.10"
          },
          "versions": [
            "1.1.4-1",
            "1.3.0-1"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-54787.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "golang-github-sigstore-sigstore-go-dev",
                "binary_version": "1.3.0-1"
              },
              {
                "binary_name": "sigstore-go",
                "binary_version": "1.3.0-1"
              }
            ]
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "sigstore-go",
            "purl": "pkg:deb/ubuntu/sigstore-go?arch=source&distro=esm-apps%2Fresolute",
            "ecosystem": "Ubuntu:Pro:26.04:LTS"
          },
          "versions": [
            "0.7.1-2",
            "0.7.3-1",
            "0.7.3-2",
            "1.1.4-1",
            "1.1.4-1ubuntu0.26.04.1~esm1"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-54787.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "golang-github-sigstore-sigstore-go-dev",
                "binary_version": "1.1.4-1ubuntu0.26.04.1~esm1"
              },
              {
                "binary_name": "sigstore-go",
                "binary_version": "1.1.4-1ubuntu0.26.04.1~esm1"
              }
            ]
          }
        }
      ],
      "modified": "2026-10-17T13:00:26.494566325Z",
      "provider": "osv",
      "upstream": [
        "CVE-2026-54787"
      ],
      "references": [
        "https://ubuntu.com/security/CVE-2026-54787",
        "https://www.cve.org/CVERecord?id=CVE-2026-54787",
        "https://github.com/sigstore/sigstore-go/security/advisories/GHSA-wqqc-jjcq-vfxm",
        "https://github.com/sigstore/sigstore-go/pull/642",
        "https://github.com/sigstore/sigstore-go/commit/4594ab4c779d08be1f4419803a8249188f35ed5f",
        "https://github.com/sigstore/sigstore-go/releases/tag/v1.2.1"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2026-54787",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 360546,
  "published_at": "2026-07-31T23:17:00+00:00"
}