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.

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-4c29-8rgm-jvjj BuildKit's Malicious frontend can cause file escape outside of storage root
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Fri, 27 Mar 2026 12:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

threat_severity

Moderate


Fri, 27 Mar 2026 08:45:00 +0000

Type Values Removed Values Added
First Time appeared Moby
Moby buildkit
Vendors & Products Moby
Moby buildkit

Fri, 27 Mar 2026 04:00:00 +0000

Type Values Removed Values Added
Description 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.
Title BuildKit vulnerable to malicious frontend causing file escape outside of storage root
Weaknesses CWE-22
References
Metrics cvssV3_1

{'score': 8.4, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-03-27T00:49:06.165Z

Reserved: 2026-03-23T18:30:14.124Z

Link: CVE-2026-33747

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-03-27T01:16:21.330

Modified: 2026-03-27T01:16:21.330

Link: CVE-2026-33747

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-03-27T00:49:06Z

Links: CVE-2026-33747 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-03-27T09:22:25Z

Weaknesses