Is CVE-2026-34165 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-34165 being exploited in the wild.

How severe is CVE-2026-34165?

Medium severity, with a CVSS score of 5, 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) SEMVER:introduced=5.0.0,fixed=5.17.1.

Is there a fix for CVE-2026-34165?

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-2026-34165 attacked?

It is attacked with local access, in a software library.

Am I affected by CVE-2026-34165?

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.

CVE-2026-34165: go-git denial of service via crafted .idx file

CVE-2026-34165 · Severity: medium · CVSS 5 · Published 2026-03-31

go-git is a software library used by developers to integrate Git functionality into Go-based applications. A vulnerability in how the library handles specific Git index files could allow an attacker with local access to crash the application by exhausting its memory. This results in a denial-of-service, potentially disrupting development workflows or services that rely on the library to process repository data.

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-2026-34165 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-34165 being exploited in the wild.
How severe is CVE-2026-34165?: Medium severity, with a CVSS score of 5, 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) SEMVER:introduced=5.0.0,fixed=5.17.1.
Is there a fix for CVE-2026-34165?: 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-2026-34165 attacked?: It is attacked with local access, in a software library.
Am I affected by CVE-2026-34165?: 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 handling of Git index (.idx) files due to an integer underflow (CWE-191) and lack of resource limits (CWE-770). By providing a maliciously crafted .idx file, an attacker can trigger excessive memory allocation, leading to a denial-of-service (DoS) via memory exhaustion. Exploitation requires the attacker to have local write access to the .git directory of a repository to place or modify the .idx file, and requires the victim to interact with the repository using the vulnerable library. The issue is rooted in the plumbing/format/idxfile component and has been addressed in version 5.17.1 by improving version and fanout checks.

Affected products

go-git project go-git >= 5.0.0, < 5.17.1

Identifiers

CVE-2026-34165
GHSA-jhf3-xxhw-2wpp
GO-2026-4910

Timeline

2026-03-29: patched: Version 5.17.1 released.
2026-03-31: disclosed: Public advisory published.

References

This page as Markdown. Free to reuse under CC BY 4.0 with a link back.