CVE-2026-25934: go-git improperly verifies data integrity values for .idx and .pack files

Severity: medium (CVSS 4.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-02-09 · updated 2026-06-17
Weakness: CWE-354

Description

go-git is a highly extensible git implementation library written in pure Go. Prior to 5.16.5, a vulnerability was discovered in go-git whereby data integrity values for .pack and .idx files were not properly verified. This resulted in go-git potentially consuming corrupted files, which would likely result in unexpected errors such as object not found. For context, clients fetch packfiles from upstream Git servers. Those files contain a checksum of their contents, so that clients can perform integrity checks before consuming it. The pack indexes (.idx) are generated locally by go-git, or the git cli, when new .pack files are received and processed. The integrity checks for both files were not being verified correctly. This vulnerability is fixed in 5.16.5.

Affected products

go-git: before 5.16.5 — fixed in 5.16.5

How to fix

Upgrade to a fixed version: go-git 5.16.5. Check the vendor advisory for mitigations.

References

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