moby buildkit up to 0.28.0 Image Parser path traversal

Summaryinfo

A vulnerability has been found in moby buildkit up to 0.28.0 and classified as critical. This issue affects some unknown processing of the component Image Parser. This manipulation causes path traversal. This vulnerability is tracked as CVE-2026-33747. The attack is restricted to local execution. No exploit exists. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in moby buildkit up to 0.28.0. It has been declared as critical. Affected by this vulnerability is an unknown part of the component Image Parser. The manipulation with an unknown input leads to a path traversal vulnerability. The CWE definition for the vulnerability is CWE-22. The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE 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 advisory is shared at github.com. This vulnerability is known as CVE-2026-33747 since 03/23/2026. The exploitation appears to be easy. An attack has to be approached locally. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1006 for this issue.

The vulnerability scanner Nessus provides a plugin with the ID 310540 (Fedora 44 : moby-engine (2026-853a2fa7e5)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 0.28.1 eliminates this vulnerability. The upgrade is hosted for download at github.com.

The vulnerability is also documented in the databases at Tenable (310540) and CERT Bund (WID-SEC-2026-0873). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Affected

• Google Container-Optimized OS
• Amazon Linux 2
• Red Hat Enterprise Linux
• Fedora Linux
• Ubuntu Linux
• SUSE Linux
• SUSE openSUSE
• IBM MQ
• Open Source docker
• Red Hat OpenShift

Productinfo

Vendor

• moby

Name

• buildkit

Version

• 0.1
• 0.2
• 0.3
• 0.4
• 0.5
• 0.6
• 0.7
• 0.8
• 0.9
• 0.10
• 0.11
• 0.12
• 0.13
• 0.14
• 0.15
• 0.16
• 0.17
• 0.18
• 0.19
• 0.20
• 0.21
• 0.22
• 0.23
• 0.24
• 0.25
• 0.26
• 0.27
• 0.28.0

Website

• Product: https://github.com/moby/buildkit/

CPE 2.3info

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CPE 2.2info

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Entryinfo

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