CVE-2026-44309

MediumCVSS 5.3

Published: 15/05/2026(UTC)Updated: 26/10/2026(UTC)Translated: 26/10/2026(UTC)NVD NIST

Exploitation Probability (EPSS)

Low risk

0.12%

2th percentile - higher than 2% of all known CVEs

Summary

Gitsign is a keyless Sigstore signing tool for Git commits with 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; for malformed objects with duplicate tree headers, git-core and go-git parse different trees, so a signature over the go-git-normalized form passes verification while git-core resolves a different tree. This is fixed in 0.16.0.

Risk Assessment

A signature may be accepted that actually refers to different content than git-core presents, undermining trust in signature verification.

Recommendation

Update Gitsign to version 0.16.0 or later.

Other vulnerabilities in Gitsign

CVE-2026-44310Medium
Gitsign is a keyless Sigstore signing tool for Git commits with a GitHub/OIDC identity. From 0.4.0 to before 0.15.0, CertVerifier.Verify() unconditionally dereferences certs[0] after sd.GetCertificates() without checking the slice length; a CMS/PKCS7 signed message with an empty certificate set causes an index-out-of-range panic that is silently recovered on the gitsign --verify path, returning exit code 0 and causing failed verification to be interpreted as success. This is fixed in 0.15.0.

Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS