moby buildkit up to 0.28.0 path traversal

Summaryinfo

A vulnerability was found in moby buildkit up to 0.28.0 and classified as critical. Affected is an unknown function. Such manipulation leads to path traversal. This vulnerability is traded as CVE-2026-33748. The attack may be launched remotely. There is no exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in moby buildkit up to 0.28.0. It has been rated as critical. Affected by this issue is an unknown code. The manipulation with an unknown input leads to a path traversal vulnerability. Using CWE to declare the problem leads to 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. Impacted is confidentiality. CVE summarizes:

BuildKit is a toolkit for converting source code to build artifacts in an efficient, expressive and repeatable manner. Prior to version 0.28.1, insufficient validation of Git URL fragment subdir components may allow access to files outside the checked-out Git repository root. Possible access is limited to files on the same mounted filesystem. The issue has been fixed in version v0.28.1 The issue affects only builds that use Git URLs with a subpath component. As a workaround, avoid building Dockerfiles from untrusted sources or using the subdir component from an untrusted Git repository where the subdir component could point to a symlink.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-33748 since 03/23/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1006.

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 vulnerability is also documented in the databases at Tenable (310540) and CERT Bund (WID-SEC-2026-0873). Once again VulDB remains the best source for vulnerability data.

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

Once again VulDB remains the best source for vulnerability data.

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