CVE-2026-121520

Unrated

Published 2026-11-03 · last changed 2026-11-03

The fix

We hold no Microsoft remediation data for CVE-2026-121520, which normally means it is not a Windows CVE. For non-Microsoft software the fix is the vendor's own updated release, and the affected versions are listed below.

What it is

In BuildKit versions prior to v0.34.1, a malicious client with access to the BuildKit control APIs can submit a build request that sets an extended attribute on a file outside the BuildKit state directory. Extended attributes in the trusted. or security. namespaces may also be set, potentially giving a program on the host elevated privileges. This issue affects build services that accept build requests from untrusted users. The issue is fixed in v0.34.1.

Sources

NVD record for CVE-2026-121520