{"id":"CVE-2026-49834","revision":null,"records":[{"revision":"51562abe5ad4401e955336fde6b8cf85","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-49834","aliases":[],"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.","state":0,"publishedAt":"2026-07-17T19:20:06.14+00:00","modifiedAt":"2026-07-17T19:42:17.005+00:00","affected":[{"ecosystem":"Vendor product","name":"sigstore-go","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"sigstore\",\n                    \"product\": \"sigstore-go\",\n                    \"versions\": [\n                        {\n                            \"version\": \"< 1.2.0\",\n                            \"status\": \"affected\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N","score":5.9,"severity":"MEDIUM"}],"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"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-49834","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-49834","identifiers":["CVE-2026-49834"]},"retained":false,"historicalAffected":[]},{"revision":"b7b5ecbf0f6448f6ada160a741452abe","observedAt":"2026-10-25T12:17:38.331+00:00","statement":{"source":"nvd","id":"CVE-2026-49834","aliases":[],"title":"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…","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.","state":0,"publishedAt":"2026-07-17T20:17:21.963+00:00","modifiedAt":"2026-10-24T20:10:00.137+00:00","affected":[],"metrics":[{"system":"CVSS 3.1 · security-advisories@github.com · Secondary","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N","score":5.9,"severity":"MEDIUM"},{"system":"CVSS 3.1 · nvd@nist.gov · Primary","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","score":7.5,"severity":"HIGH"}],"references":["https://github.com/sigstore/sigstore-go/commit/dbb07e62623edd5b175fb9dd5a41dcb85a159207","https://github.com/sigstore/sigstore-go/pull/633","https://github.com/sigstore/sigstore-go/releases/tag/v1.2.0","https://github.com/sigstore/sigstore-go/security/advisories/GHSA-9vcr-p3rj-q5q6"],"sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-49834","license":"NIST NVD usage terms; underlying source attribution retained","enrichment":{"sourceStatus":"Analyzed","weaknesses":["CWE-347"],"productCriteria":["cpe:2.3:a:sigstore:sigstore-go:*:*:*:*:*:*:*:*"],"sourceDates":{"published":"2026-07-17T20:17:21.963","lastModified":"2026-10-24T20:10:00.137"},"relatedAdvisories":[],"note":"NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON."},"key":"nvd:CVE-2026-49834","identifiers":["CVE-2026-49834"]},"retained":false,"historicalAffected":[]},{"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":[]},{"revision":"ec2eb4fef68c4c97a9a070e5803fae21","observedAt":"2026-10-24T13:19:41.952+00:00","statement":{"source":"osv","id":"GO-2026-5952","aliases":["CVE-2026-49834","GHSA-9vcr-p3rj-q5q6"],"title":"sigstore-go has a multi-log threshold bypass via single compromised log in github.com/sigstore/sigstore-go","description":"sigstore-go has a multi-log threshold bypass via single compromised log in github.com/sigstore/sigstore-go","state":0,"publishedAt":"2026-07-17T19:42:05+00:00","modifiedAt":"2026-07-23T16:31:01.7932627+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":[],"references":["https://github.com/sigstore/sigstore-go/security/advisories/GHSA-9vcr-p3rj-q5q6"],"sourceUrl":"https://osv.dev/vulnerability/GO-2026-5952","license":"OSV · upstream source license applies","key":"osv:GO-2026-5952","identifiers":["GO-2026-5952","CVE-2026-49834","GHSA-9vcr-p3rj-q5q6"]},"retained":false,"historicalAffected":[]}],"coverage":[{"source":"cisa-kev:global","scope":"Complete CISA KEV catalog; all vendors. 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