Quick answers
- Is CVE-2026-15791 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-15791 being exploited in the wild.
- How severe is CVE-2026-15791?
- Informational severity, with a CVSS score of 1.8, published 21 July 2026.
- Which products and versions are affected?
- Moby Project BuildKit >= 0.10.0, < 0.31.2.
- Is there a fix for CVE-2026-15791?
- A patch was published on 2026-07-16: Fixed in version 0.31.2 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-15791 attacked?
- It is attacked with local access, in a software library.
- Am I affected by CVE-2026-15791?
- Check whether you run Moby Project BuildKit 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.
Technical details
A path traversal vulnerability (CWE-22) exists in the BuildKit low-level build (LLB) API. The root cause is improper validation of file operation messages, which allows a delete action intended for the build container's rootfs to escape into the host's /tmp directory. Exploitation requires the attacker to use a custom BuildKit frontend to send a crafted LLB message; the vulnerability is not reachable via standard Dockerfile builds. Successful exploitation results in the unauthorized removal of contents within the host's temporary directory. The issue is patched in BuildKit version 0.31.2.
Affected products
- Moby BuildKit >= 0.10.0, < 0.31.2
Timeline
- 2026-07-16: advisory: GitHub Security Advisory published
- 2026-07-21: disclosed: NVD publication date
- 2026-07-16: patched: Fixed in version 0.31.2