CVE-2026-34165 go-git: Maliciously crafted idx file can cause asymmetric memory consumption
A maliciously crafted .idx file in go-git can cause asymmetric memory consumption, leading to a denial-of-service condition.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-34165?
CVE-2026-34165 is a medium-severity denial of service vulnerability in go-git, published on 31 Mar 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
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.
Which versions are affected by CVE-2026-34165?
5 open source packages ship an affected version, including github.com/go-git/go-git/v5, github.com/go-git/go-git and github.com/go-git/go-git/v4. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/go-git/go-git/v5 Go | From 5.0.0 | 5.17.1 |
github.com/go-git/go-git/v5 Go | From 5.0.0 | 5.17.1 |
github.com/go-git/go-git/v5 Go | From 5.0.0 | 5.17.1 |
github.com/go-git/go-git Go | All versions | None |
github.com/go-git/go-git/v4 Go | All versions | None |
Products include Go-Git Project Go-Git.
How do I fix CVE-2026-34165?
Upgrade github.com/go-git/go-git/v5 to 5.17.1 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-34165 being exploited?
There is no known exploitation of CVE-2026-34165 in the wild and no public exploit code.
Other vulnerabilities in go-git
- CVE-2023-49569 Maliciously crafted Git server replies can lead to path traversal and RCE on go-git clients
- CVE-2025-21613 go-git has an Argument Injection via the URL field
- CVE-2025-21614 go-git clients vulnerable to DoS via maliciously crafted Git server replies
- CVE-2023-49568 Maliciously crafted Git server replies can cause DoS on go-git clients
- CVE-2026-45022 go-git: Improper parsing of specially crafted objects may lead to inconsistent interpretation compared to upstream Git
Sources
Also known as CLEANSTART-2026-NA70806, CLEANSTART-2026-QJ54247, CLEANSTART-2026-ZE87460, DEBIAN-CVE-2026-34165, GHSA-jhf3-xxhw-2wpp, GO-2026-4910 and 118 more.