{"id":"CVE-2026-54787","summary":"sigstore-go fails to check signature timestamps against a signing key's validity period","details":"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.","aliases":["GHSA-wqqc-jjcq-vfxm"],"modified":"2026-08-04T11:49:51.443279532Z","published":"2026-07-31T21:58:14.156Z","related":["CGA-wxx3-qjx8-5q63"],"database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-324"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54787.json"},"references":[{"type":"WEB","url":"https://github.com/sigstore/sigstore-go/releases/tag/v1.2.1"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54787.json"},{"type":"ADVISORY","url":"https://github.com/sigstore/sigstore-go/security/advisories/GHSA-wqqc-jjcq-vfxm"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-54787"},{"type":"FIX","url":"https://github.com/sigstore/sigstore-go/commit/4594ab4c779d08be1f4419803a8249188f35ed5f"},{"type":"FIX","url":"https://github.com/sigstore/sigstore-go/pull/642"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/sigstore/sigstore-go","events":[{"introduced":"0"},{"fixed":"4594ab4c779d08be1f4419803a8249188f35ed5f"}],"database_specific":{"source":"AFFECTED_FIELD","extracted_events":[{"introduced":"0"},{"fixed":"1.2.1"}]}}],"versions":["v1.2.0","v1.1.4","v1.1.3","v1.1.2","v1.1.1","v1.1.0","v1.0.0","v0.7.3","v0.7.2","v0.7.1","v0.7.0","v0.6.2","v0.6.1","v0.6.0","v0.5.1","v0.5.0","v0.4.0","v0.3.0","v0.2.0","v0.1.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-54787.json"}}],"schema_version":"1.8.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N"}]}