Impact "go-git" may parse malformed Git objects in a way that differs from upstream Git. When "commit" or "tag" objects contain ambiguous or malformed headers, "go-git"’s decoded representation may expose values differently from how Git itself would interpret or reject the same object. Additionally, "go-git"’s commit signing and verification logic operates over commit data reconstructed from "go-git"’s parsed representation rather than the original raw object bytes. As a result, "go-git" may sign or verify a commit payload that is not byte-for-byte equivalent to the object stored in the repository. This can cause a signature to appear valid for a commit whose displayed or effective metadata differs from the object that was intended to be signed. Patches Users should upgrade to a patched version in order to mitigate this vulnerability. Versions prior to v5 are likely to be affected, users are recommended to upgrade to a supported "go-git" version. Credit Thanks to @bugbunny-research (https://bugbunny.ai/) for reporting this to "sigstore/gitsign", and to @wlynch, @patzielinski and @adityasaky for coordinating the disclosure with the "go-git" project. :bow: :1st_place_medal: Thanks to @wayphinder for reporting this to the "go-git" project. :bow: