CVE-2026-15791: LLB file operation can be tricked to remove /tmp directory contents

Published Jul 21, 2026
·
Updated

A crafted message in the BuildKit low-level build API can be used to remove the contents of the /tmp directory. The action that can normally be used to delete files inside the build container rootfs can escape into the real host temp directory.

Affected Software

2 affected components
Docker BuildKit
Mobyproject Buildkit<0.31.2

Event History

Jul 21, 2026
CVE Published
via MITRE·04:10 PM
Data Sourced
via MITRE·04:10 PM
DescriptionWeakness
Data Sourced
via NVD·05:17 PM
DescriptionSeverityWeaknessAffected Software

Frequently Asked Questions

1

What is the severity of CVE-2026-15791?

CVE-2026-15791 has a severity rating of low with a CVSS score of 4.0.

2

How does CVE-2026-15791 impact Docker BuildKit?

CVE-2026-15791 allows a crafted message to remove contents from the /tmp directory of the host when using Docker BuildKit.

3

How can I mitigate CVE-2026-15791?

Mitigation for CVE-2026-15791 involves ensuring that Docker BuildKit is not used in contexts where untrusted input can be processed.

4

Is it necessary to patch CVE-2026-15791?

While the severity is low, it is advisable to patch or apply appropriate mitigations to avoid potential data loss.

5

What software is affected by CVE-2026-15791?

CVE-2026-15791 affects Docker BuildKit, specifically versions that allow path traversal vulnerabilities.

Contact

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