Low 2 vendors · 2 advisories

CVE-2026-121542: Bake filesystem path entitlements approval can be skipped for path using basename prefix

CVE-2026-121542 key facts

CISA KEV: Not listed (catalogue checked Nov 10, 2026)
Highest advisory rating: Low
CVSS base score: 2.5 (Red Hat), 1.8 (Docker)
CVSS vector: CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N · base score 1.8, scored by DockerAttack vector: local. Attack complexity: low. Attack requirements: present. Privileges required: none. User interaction: active. Confidentiality impact on the vulnerable system: low. Integrity impact on the vulnerable system: none. Availability impact on the vulnerable system: none. Confidentiality impact on subsequent systems: none. Integrity impact on subsequent systems: none. Availability impact on subsequent systems: none.
Weakness: CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CISA SSVC: Exploitation: none observed. Automatable: no. Technical impact: partial. CISA, Nov 4, 2026.
Fixed releases: Docker: 0.38.1
Red Hat: 38.1
Vendor advisories: 2 from Docker, Red Hat
Assigned by: Docker (CNA)
CVE record published: Nov 3, 2026
Listed by VulniPulse: Nov 3, 2026
Record changed: Nov 6, 2026

Ratings, versions and fixes are quoted from the vendor advisories that cover only CVE-2026-121542; each belongs to its advisory, not to every product listed. How records are collected and checked.

Description

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.

Text from the CVE.org record (Docker).

How do I fix CVE-2026-121542?

Upgrade to a fixed release named by the vendor:

Docker: 0.38.1
Red Hat: 38.1

Upgrade to Docker Buildx v0.38.1 or later. As a workaround, run only trusted Bake build definitions (per upstream advisory GHSA-rghq-x9hf-hc3r). (Red Hat)
Upgrade Docker Buildx to v0.38.1 or later. (CVE.org record)
Workaround: Run only trusted Bake definitions until upgrading. Check that Bake definitions do not contain suspicious paths outside trusted directories. The issue requires specific matching filenames next to the current project directory. (CVE.org record)

Vendor advisories for CVE-2026-121542

Docker

1 advisory

Advisory severityLow1.8
Low [CVE-2026-121542] 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
CVE-2026-121542Source published Nov 3, 2026Source updated Nov 6, 2026
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.
Affected products in this advisory
Docker Buildx
Source-reported affected versions
through 0.38.0
Source-reported fixed versions
0.38.1
Mitigation guidance
No mitigation guidance extracted; consult the source.
Full advisory and evidence Open source bulletin

Red Hat

1 advisory

Advisory severityLow2.5
Low [CVE-2026-121542] Information disclosure via filesystem entitlement check bypass
CVE-2026-121542Source published Nov 3, 2026Source updated Nov 3, 2026
Information disclosure via filesystem entitlement check bypass. Red Hat rates this low (CVSS 2.5). Weakness: CWE-22. Affected product named by the advisory: Red Hat Ceph Storage 9.
Related products — impact not confirmed
Red Hat Ceph Storage 9
Source-reported affected versions
19.0
38.0
Source-reported fixed versions
38.1
Mitigation guidance
Upgrade to Docker Buildx v0.38.1 or later. As a workaround, run only trusted Bake build definitions (per upstream advisory GHSA-rghq-x9hf-hc3r).
Full advisory and evidence Open source bulletin

References

CVE-2026-121542 recordCVE.org
CVE-2026-121542 detailNVD
github.com/docker/buildx/security/advisories/GHSA-rghq-x9hf-hc3rvendor-advisory

Timeline

Nov 3, 2026CVE record published
Nov 3, 2026First vendor advisory listed by VulniPulse
Nov 4, 2026CVE record last updated

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