{"id":"CVE-2026-49834","state":"PUBLISHED","title":"sigstore-go: Multi-log threshold bypass via single compromised log","description":"sigstore-go is a Go library for Sigstore signing and verification. Prior to 1.2.0, a verifier configured with WithTransparencyLog(N>1) or WithSignedCertificateTimestamps(N>1) counts verified witnesses per entry or per validation path rather than per log authority, allowing a single compromised transparency log or CT log to satisfy multi-log threshold requirements and defeat the multi-log policy. This issue is fixed in version 1.2.0.","publishedAt":"2026-07-17T19:20:06.140Z","updatedAt":"2026-07-17T19:42:17.005Z","severity":{"score":5.9,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["sigstore sigstore-go"],"affected":[{"vendor":"sigstore","product":"sigstore-go","versions":[{"version":"< 1.2.0","status":"affected"}]}],"references":["https://github.com/sigstore/sigstore-go/security/advisories/GHSA-9vcr-p3rj-q5q6","https://github.com/sigstore/sigstore-go/pull/633","https://github.com/sigstore/sigstore-go/commit/dbb07e62623edd5b175fb9dd5a41dcb85a159207","https://github.com/sigstore/sigstore-go/releases/tag/v1.2.0"],"weaknesses":["CWE-347"],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/49xxx/CVE-2026-49834.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-49834","state":"PUBLISHED","datePublished":"2026-07-17T19:20:06.140Z","dateUpdated":"2026-07-17T19:42:17.005Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-01T18:50:36.056Z"},"containers":{"cna":{"title":"sigstore-go: Multi-log threshold bypass via single compromised log","descriptions":[{"lang":"en","value":"sigstore-go is a Go library for Sigstore signing and verification. Prior to 1.2.0, a verifier configured with WithTransparencyLog(N>1) or WithSignedCertificateTimestamps(N>1) counts verified witnesses per entry or per validation path rather than per log authority, allowing a single compromised transparency log or CT log to satisfy multi-log threshold requirements and defeat the multi-log policy. This issue is fixed in version 1.2.0."}],"affected":[{"vendor":"sigstore","product":"sigstore-go","versions":[{"version":"< 1.2.0","status":"affected"}]}],"references":[{"url":"https://github.com/sigstore/sigstore-go/security/advisories/GHSA-9vcr-p3rj-q5q6","name":"https://github.com/sigstore/sigstore-go/security/advisories/GHSA-9vcr-p3rj-q5q6","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/sigstore/sigstore-go/pull/633","name":"https://github.com/sigstore/sigstore-go/pull/633","tags":["x_refsource_MISC"]},{"url":"https://github.com/sigstore/sigstore-go/commit/dbb07e62623edd5b175fb9dd5a41dcb85a159207","name":"https://github.com/sigstore/sigstore-go/commit/dbb07e62623edd5b175fb9dd5a41dcb85a159207","tags":["x_refsource_MISC"]},{"url":"https://github.com/sigstore/sigstore-go/releases/tag/v1.2.0","name":"https://github.com/sigstore/sigstore-go/releases/tag/v1.2.0","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":5.9,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-347","lang":"en","description":"CWE-347: Improper Verification of Cryptographic Signature","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-07-17T19:20:06.140Z"},"source":{"advisory":"GHSA-9vcr-p3rj-q5q6","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-17T19:42:04.325650Z","id":"CVE-2026-49834","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-07-17T19:42:17.005Z"}}]}}}