Path check bypass in Docker Buildx Bake exposes unapproved files
Key facts
- Attack vector
- Local
- Privileges required
- None
- User interaction
- Active
- Attack complexity
- Low
- Attack requirements
- Present
- Impact type
- Information disclosure
- Confidentiality · integrity · availability
- Low · None · None
- Fix status
- Partial Red Hat: 1 without a fix
Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-22 and the CVSS impact.
Summary
Docker Buildx from 0.19.0 before 0.38.1 is affected. A path check flaw (CWE-22) lets an untrusted Bake definition expose files to the Buildx client without the expected fs.read approval, because paths beside the working directory whose names start with its basename skip the entitlement check. Exploitation requires specific matching filenames next to the project directory, and users who run untrusted Bake definitions may be affected.
Written with Claude Haiku 5.5 from the sources below · 2026-11-07
Description from the CNA
In Docker Buildx versions v0.19.0 through v0.38.0, an untrusted Bake definition may expose files accessible to the Buildx client without the expected fs.read approval. Under certain conditions, paths under the same parent directory as the current working directory whose names use the working directory's basename as a prefix can skip the filesystem entitlement check. Exploitation requires specific matching filenames next to the current project directory. Users who run untrusted Bake definitions may be affected. The issue is fixed in v0.38.1.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
Upgrade Docker Buildx to 0.38.1. Red Hat Ceph Storage 9 is affected without a fix, and Red Hat lists no plan available for it.
Written with Claude Haiku 5.5 from the sources below · 2026-11-07
- Fix · CNA Docker Buildx (Docker) Fixed in 0.38.1
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
Docker Buildx 0.38.1
2 records Highest priority Priority LOW 2 LOW
Other records, highest priority first
- TI-2026-84836 Filesystem entitlement check skipped in Docker Buildx Bake multi-target buildsPriority LOW 24
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Ceph Storage 9 | Affected | No fix yet: Fix deferred |
Timeline
- 2026-11-03 Threatist record created from CVE-2026-121542
- 2026-11-04 CISA SSVC decision points changed
- 2026-11-07 Affected versions changed · Red Hat
- 2026-11-07 CVSS score added · Red Hat
References
More Docker vulnerabilities
- TI-2019-11833 Docker Desktop Community Edition before 2.1.0.1 allows local users to gain privileges by… KEVCVSS 3.1HIGH 7.8
- TI-2019-04061 runc through 1.0-rc6, as used in Docker before 18.09.2 and other products, allows… CVSS 3.1HIGH 8.6
- TI-2025-08316 Docker Desktop allows unauthenticated access to Docker Engine API from containers CVSS 4.0CRITICAL 9.3
- TI-2025-02823 Elevation of Privilege in Docker Desktop for Windows during Upgrade due to Insecure Directory Deletion CVSS 4.0HIGH 7.3
- TI-2026-14229 Tar extraction in moby/go-archive can write outside the destination directory via link following CVSS 4.0HIGH 7.1
- TI-2023-21271 Docker Machine through 0.16.2 allows an attacker, who has control of a worker node, to… CVSS 3.1MEDIUM 6.5
Sources
- CVE-2026-121542 · CVE Program
- CVE-2026-121542 · NVD
- FIRST EPSS
- CVE-2026-121542 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences