CVE-2026-33747CWE-22

BuildKit vulnerable to malicious frontend causing file escape outside of storage root

High · published March 27, 2026

CVSS v3.1
8.4
EPSS
1%
Percentile
47.2
In the wild
Unconfirmed
What it is

BuildKit is a toolkit for converting source code to build artifacts in an efficient, expressive and repeatable manner. Prior to version 0.28.1, when using a custom BuildKit frontend, the frontend can craft an API message that causes files to be written outside of the BuildKit state directory for the execution context. The issue has been fixed in v0.28.1. The vulnerability requires using an untrusted BuildKit frontend set with `#syntax` or `--build-arg BUILDKIT_SYNTAX`. Using these options with a well-known frontend image like `docker/dockerfile` is not affected.

The record
Technical detail
CVSS v3.1
8.4 · HIGH
Vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00583 · 47.2th percentile
Weakness
CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Published
2026-03-27T00:49Z
EPSS history
Timeline
  • 27 MAR 00:49Z
    BuildKit vulnerable to malicious frontend causing file escape outside of storage root
    cvelistv5