{"id":"CVE-2026-44309","sourceIdentifier":"security-advisories@github.com","published":"2026-05-15T17:16:47.297","lastModified":"2026-06-17T10:50:28.723","vulnStatus":"Deferred","cveTags":[],"descriptions":[{"lang":"en","value":"Gitsign is a keyless Sigstore to signing tool for Git commits with your a GitHub / OIDC identity. Prior to 0.16.0, gitsign verify and gitsign verify-tag re-encode commit/tag objects through go-git's EncodeWithoutSignature before checking the signature, instead of verifying against the raw git object bytes. For malformed objects with duplicate tree headers, git-core and go-git parse different trees: git-core uses the first, go-git uses the second. A signature crafted over the go-git-normalized form (second tree) passes gitsign verify while git-core resolves the commit to a completely different tree. This breaks the invariant that a verified signature, the commit semantics git-core presents to users, and the object hash logged in Rekor all refer to the same content. This vulnerability is fixed in 0.16.0."}],"affected":[{"source":"security-advisories@github.com","affectedData":[{"vendor":"sigstore","product":"gitsign","versions":[{"version":"< 0.16.0","status":"affected"}]}]}],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N","baseScore":5.3,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"REQUIRED","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"HIGH","availabilityImpact":"NONE"},"exploitabilityScore":1.6,"impactScore":3.6}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-05-15T17:43:27.049597Z","id":"CVE-2026-44309","options":[{"exploitation":"poc"},{"automatable":"no"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"weaknesses":[{"source":"security-advisories@github.com","type":"Secondary","description":[{"lang":"en","value":"CWE-295"},{"lang":"en","value":"CWE-347"}]}],"references":[{"url":"https://github.com/sigstore/gitsign/security/advisories/GHSA-7rmh-48mx-2vwc","source":"security-advisories@github.com"},{"url":"https://github.com/sigstore/gitsign/security/advisories/GHSA-7rmh-48mx-2vwc","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}]}