go-git: Improper parsing of specially crafted objects may lead to inconsistent interpretation compared to upstream Git

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go-git is an extensible git implementation library written in pure Go. Prior to 5.19.0 and 6.0.0-alpha.3, 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. This vulnerability is fixed in 5.19.0 and 6.0.0-alpha.3.

Source published

27 May 2026 14:54:47 UTC

Source modified

27 May 2026 15:43:32 UTC

Saved here

23 Oct 2026 15:48:27 UTC

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CVE Program Terms of Use

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Source: cve-program · CVE Program Terms of Use. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.

CVSS 4.0 · 7.0 CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N

go-git is an extensible git implementation library written in pure Go. Prior to 5.19.0 and 6.0.0-alpha.3, 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. This vulnerability is fixed in 5.19.0 and 6.0.0-alpha.3.

Source published

May 27, 2026, 2:54:47 PM (timezone not stated)

Source modified

May 27, 2026, 3:43:32 PM (timezone not stated)

Saved here

15 Nov 2026 16:45:36 UTC

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ENISA EUVD · source terms and attribution apply

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Source: euvd · ENISA EUVD · source terms and attribution apply. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.

EUVD CVSS 4.0 · 7.0 CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N

go-git is an extensible git implementation library written in pure Go. Prior to 5.19.0 and 6.0.0-alpha.3, 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. This vulnerability is fixed in 5.19.0 and 6.0.0-alpha.3.

Source published

27 May 2026 15:16:29 UTC

Source modified

17 Jun 2026 10:51:36 UTC

Saved here

25 Oct 2026 10:17:33 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

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Source: nvd · NIST NVD usage terms; underlying source attribution retained. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.

CVSS 4.0 · [email protected] · Secondary · 7.0 CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS 3.1 · [email protected] · Primary · 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

### 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:

Source published

11 May 2026 14:48:12 UTC

Source modified

10 Sep 2026 03:51:04 UTC

Saved here

24 Oct 2026 13:19:41 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

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Source: osv · GitHub Advisory Database · CC-BY-4.0. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.

CVSS_V4 · CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N

Publisher rating · HIGH

Go-git: Improper parsing of specially crafted objects may lead to inconsistent interpretation in github.com/go-git/go-git

Source published

24 Jul 2026 18:35:55 UTC

Source modified

8 Aug 2026 21:41:54 UTC

Saved here

24 Oct 2026 13:19:41 UTC

Source terms

OSV · upstream source license applies

Original source record · Cite this exact observation · Complete original publisher JSON

Source: osv · OSV · upstream source license applies. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.