{"id":"GHSA-9vcr-p3rj-q5q6","revision":"93591aae30a2464486160194235eddac","records":[{"revision":"93591aae30a2464486160194235eddac","observedAt":"2026-10-24T13:19:41.952+00:00","statement":{"source":"osv","id":"GHSA-9vcr-p3rj-q5q6","aliases":["CVE-2026-49834","GO-2026-5952"],"title":"sigstore-go has a multi-log threshold bypass via single compromised log","description":"### Impact\n_What kind of vulnerability is it? Who is impacted?_\n\nA verifier configured with WithTransparencyLog(N>1) or WithSignedCertificateTimestamps(N>1) expected defense-in-depth against the compromise of a single log instance. However, threshold counting counted verified witnesses per-entry or per-validation-path rather than per-log-authority.\n\nAs a result, a single compromised transparency log could forge multiple entries with different indices, and a single compromised CT log could verify multiple times (either across multiple certificate chains or via multiple embedded SCTs), fully satisfying the multi-log threshold requirements and defeating the multi-log policy.\n\nNote that this does not affect Cosign, as Cosign sets a threshold of 1.\n\n### Patches\n_Has the problem been patched? What versions should users upgrade to?_\n\nUpgrade to v1.1.5.\n\n### Workarounds\n_Is there a way for users to fix or remediate the vulnerability without upgrading?_\n\nThere is no workaround, beyond relying on trusted logs.","state":0,"publishedAt":"2026-07-09T23:20:30+00:00","modifiedAt":"2026-09-10T03:51:11.3565741+00:00","affected":[{"ecosystem":"Go","name":"github.com/sigstore/sigstore-go","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"0"},{"kind":"fixed","version":"1.2.0"}]}],"versions":[],"rawVersionEvidence":null}],"metrics":[{"system":"CVSS_V3","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N","score":null,"severity":null},{"system":"Publisher rating","vector":null,"score":null,"severity":"MODERATE"}],"references":["https://github.com/sigstore/sigstore-go/security/advisories/GHSA-9vcr-p3rj-q5q6","https://nvd.nist.gov/vuln/detail/CVE-2026-49834","https://github.com/sigstore/sigstore-go/pull/633","https://github.com/sigstore/sigstore-go/commit/dbb07e62623edd5b175fb9dd5a41dcb85a159207","https://github.com/sigstore/sigstore-go","https://github.com/sigstore/sigstore-go/releases/tag/v1.2.0"],"sourceUrl":"https://github.com/advisories/GHSA-9vcr-p3rj-q5q6","license":"GitHub Advisory Database · CC-BY-4.0","key":"osv:GHSA-9vcr-p3rj-q5q6","identifiers":["GHSA-9vcr-p3rj-q5q6","CVE-2026-49834","GO-2026-5952"]},"retained":false,"historicalAffected":[]}],"coverage":[]}