{"cve":"CVE-2026-44309","nvd":{"published":"2026-05-15T17:16:47.297","modified":"2026-10-26T14:10:00.130","status":"Deferred","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N","score":5.3},"cwes":["CWE-295","CWE-347"],"references":["https://github.com/sigstore/gitsign/security/advisories/GHSA-7rmh-48mx-2vwc","https://github.com/sigstore/gitsign/security/advisories/GHSA-7rmh-48mx-2vwc"],"products":[],"source":"nvd","synced_at":"2026-10-26T14:27:29.784594657+00:00"},"epss":{"cve":"CVE-2026-44309","score":0.00119,"percentile":0.01736,"date":"2026-10-26"},"kev":null,"osv":[{"id":"GHSA-7rmh-48mx-2vwc","url":"https://osv.dev/vulnerability/GHSA-7rmh-48mx-2vwc","summary":"gitsign verify accepts signatures over go-git-normalized bytes, enabling trust confusion on malformed commits","modified":"2026-09-10T03:50:46.265914658Z","packages":[{"ecosystem":"Go","name":"github.com/sigstore/gitsign","purl":"pkg:golang/github.com/sigstore/gitsign","ranges":["<0.16.0"],"fixed":["0.16.0"]}]},{"id":"GO-2026-5233","url":"https://osv.dev/vulnerability/GO-2026-5233","summary":"gitsign verify accepts signatures over go-git-normalized bytes, enabling trust confusion on malformed commits in github.com/sigstore/gitsign","modified":"2026-06-25T19:45:17.508412807Z","packages":[{"ecosystem":"Go","name":"github.com/sigstore/gitsign","purl":"pkg:golang/github.com/sigstore/gitsign","ranges":["<0.16.0"],"fixed":["0.16.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}