CVE-2026-61712 BuildKit: Possible runtime DoS via unbounded group parsing
A malicious base image can cause BuildKit to exhaust memory and crash by providing oversized group files during user resolution.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-61712?
CVE-2026-61712 is a low-severity denial of service vulnerability in moby buildkit, published on 19 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
BuildKit is a toolkit for converting source code to build artifacts in an efficient, expressive and repeatable manner. Prior to 0.31.1, BuildKit read attacker-controlled /etc/passwd and /etc/group files without an upper bound while resolving a username to a user identifier or group identifier in executor/oci/user.go and solver/llbsolver/ops/user_linux.go. A malicious base image or build could provide oversized files that exhausted memory during user resolution and caused out-of-memory termination of the buildkitd process. This issue is fixed in version 0.31.1.
Weakness: CWE-770
Which versions are affected by CVE-2026-61712?
3 open source packages ship an affected version, including github.com/moby/buildkit.
| Package | Affected | Fixed in |
|---|---|---|
github.com/moby/buildkit Go | All versions | 0.31.1 |
github.com/moby/buildkit Go | All versions | 0.31.1 |
github.com/moby/buildkit Go | All versions | 0.31.1 |
How do I fix CVE-2026-61712?
Upgrade github.com/moby/buildkit to 0.31.1 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-2026-61712 being exploited?
There is no known exploitation of CVE-2026-61712 in the wild and no public exploit code.
Sources
Also known as AZL-97029, ECHO-b91e-82b4-59d9, GHSA-72x6-4j93-7w86, GO-2026-6256, MINI-237g-xfvh-2wjx, MINI-2pjf-v57f-wx3w and 41 more.