CVE-2026-33762: go-git out-of-bounds read in Git index v4 decoder

CVE-2026-33762 · Severity: low · CVSS 3.1 · Published 2026-03-31

go-git is a software library used by developers to build Git-related features into their applications. A flaw in how the library reads specific Git index files allows a specially crafted file to crash the application. This could lead to a denial-of-service where the application stops responding or shuts down unexpectedly when processing a malicious repository.

Technologies: github.com/go-git/go-git (Go), github.com/go-git/go-git/v4 (Go), github.com/go-git/go-git/v5 (Go). Vendors: Go.

Quick answers

Is CVE-2026-33762 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-33762 being exploited in the wild.
How severe is CVE-2026-33762?
Low severity, with a CVSS score of 3.1, published 31 March 2026.
Which products and versions are affected?
github.com/go-git/go-git (Go) SEMVER:introduced=0; github.com/go-git/go-git/v4 (Go) SEMVER:introduced=0; github.com/go-git/go-git/v5 (Go) <= 5.17.0, SEMVER:introduced=0,fixed=5.17.1.
Is there a fix for CVE-2026-33762?
Yes. github.com/go-git/go-git/v5 (Go): upgrade to 5.17.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-33762 attacked?
It is attacked with local access, in a software library.
Am I affected by CVE-2026-33762?
Check whether you run github.com/go-git/go-git (Go), github.com/go-git/go-git/v4 (Go) or github.com/go-git/go-git/v5 (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • github.com/go-git/go-git/v5 (Go): upgrade to 5.17.1 or later
    go get github.com/go-git/go-git/v5@v5.17.1

Technical details

A vulnerability exists in go-git's index decoder for Git index format version 4 (CWE-129). The decoder fails to validate the path name prefix length before applying it to previously decoded path names during delta compression processing. An attacker with the ability to provide a maliciously crafted .git/index file can trigger an out-of-bounds slice operation. This results in a Go runtime panic, leading to a denial-of-service (DoS) if the application does not implement panic recovery. The issue is specific to index format v4; versions v2 and v3 are unaffected. The vulnerability is addressed in version 5.17.1.

Affected products

  • go-git project go-git < 5.17.1

Identifiers

  • CVE-2026-33762
  • GHSA-gm2x-2g9h-ccm8
  • GO-2026-4909

Timeline

  • 2026-03-29: patched: Version 5.17.1 released
  • 2026-03-31: advisory: GitHub Security Advisory published
  • 2026-03-31: disclosed: CVE-2026-33762 published

References

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