go-git: Maliciously crafted idx file can cause asymmetric memory consumption

Open Source Vulnerabilities CVE-2026-34165

go-git is an extensible git implementation library written in pure Go. From version 5.0.0 to before version 5.17.1, a vulnerability has been identified in which a maliciously crafted .idx file can cause asymmetric memory consumption, potentially exhausting available memory and resulting in a denial-of-service (DoS) condition. Exploitation requires write access to the local repository's .git directory, it order to create or alter existing .idx files. This issue has been patched in version 5.17.1.

Open Source Vulnerabilities GO-2026-4910

Maliciously crafted idx file can cause asymmetric memory consumption in github.com/go-git/go-git

Open Source Vulnerabilities GHSA-jhf3-xxhw-2wpp

### Impact A vulnerability has been identified in which a maliciously crafted `.idx` file can cause asymmetric memory consumption, potentially exhausting available memory and resulting in a Denial of Service (DoS) condition. Exploitation requires write access to the local repository's `.git` directory, it order to create or alter existing `.idx` files. ### Patches Users should upgrade to `v5.17.1`, or the latest `v6` [pseudo-version](https://go.dev/ref/mod#pseudo-versions), in order to mitigate this vulnerability. ### Credit The go-git maintainers thank @kq5y for finding and reporting this issue privately to the `go-git` project.