CVE-2026-121522
In BuildKit versions v0.26.0 through v0.34.1, a specific build definition that resolves metadata for the same Git source reference twice can cause the BuildKit daemon to panic and crash, interrupting builds handled by that daemon
CVE-2026-121522: In BuildKit versions v0.26.0 through v0.34.1, a specific build definition that resolves metadata for the same Git source reference twice can…
Compare the source-linked records below. Ratings and product/version details belong to each advisory; they are not a single CVE-wide score or proof that every listed product is affected. How VulniPulse collects and checks evidence.
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CVE-2026-121522 key facts
- CISA KEV
- Not listed (catalog checked )
- Highest advisory severity
- Medium
- CVSS base score
- 6.7 (Docker), 5.5 (Red Hat)
- Weakness
- CWE-248
- Fixed releases
- Docker: 0.34.2
- VulniPulse record
- Published · Updated
Scores, vectors, weaknesses and fixed releases are quoted from vendor advisories that cover only CVE-2026-121522; bulletin-wide values are not repeated here.
Is CVE-2026-121522 exploited?
No exploitation is reported in the sources VulniPulse tracks: CVE-2026-121522 is not in the CISA KEV catalog (checked ) and no tracked advisory for it reports exploitation. That is not proof the vulnerability cannot be exploited.
How do I fix CVE-2026-121522?
Upgrade to a fixed release named by the vendor:
- Docker: 0.34.2
- Restrict build submission permissions to trusted users and avoid building untrusted definitions or repositories on shared daemon instances. In multi-tenant environments, isolate BuildKit daemon instances per workload to prevent daemon-level crashes from impacting concurrent builds. (Red Hat)
Vendor advisory comparison
Docker
1 advisory- Advisory severityMedium6.7
Medium [CVE-2026-121522] In BuildKit versions v0.26.0 through v0.34.1, a specific build definition that resolves metadata for the same Git source reference twice can cause the BuildKit daemon to panic and crash, interrupting builds handled by that daemon
CVE-2026-121522Source published Source updated
In BuildKit versions v0.26.0 through v0.34.1, a specific build definition that resolves metadata for the same Git source reference twice can cause the BuildKit daemon to panic and crash, interrupting builds handled by that daemon. The issue is fixed in v0.34.2.
- Affected products in this advisory
- BuildKit
- Source-reported affected versions
- through 0.34.1
- Source-reported fixed versions
- 0.34.2
- Mitigation guidance
- No mitigation guidance extracted; consult the source.
Red Hat
1 advisory- Advisory severityMedium5.5
Medium [CVE-2026-121522] Denial of Service via duplicate Git source metadata resolution
CVE-2026-121522Source published Source updated
Denial of Service via duplicate Git source metadata resolution. Red Hat rates this moderate (CVSS 5.5). Weakness: CWE-248. Affected products named by the advisory: Assisted Installer for Red Hat OpenShift Container Platform 2; Compliance Operator; Confidential Compute Attestation; Custom Metric Autoscaler operator for Red Hat Openshift; and 37 more.
- Related products — impact not confirmed
- Assisted Installer for Red Hat OpenShift Container Platform 2
- Compliance Operator
- Confidential Compute Attestation
- Custom Metric Autoscaler operator for Red Hat Openshift
37 more entries in the full advisory.
- Source-reported affected versions
- Affected-version details not available in this record.
- Source-reported fixed versions
- No fixed-version detail extracted. This does not mean no fix exists.
- Mitigation guidance
- Restrict build submission permissions to trusted users and avoid building untrusted definitions or repositories on shared daemon instances. In multi-tenant environments, isolate BuildKit daemon instances per workload to prevent daemon-level crashes from impacting concurrent builds.
More Docker advisories
- CVE-2026-121520Nov 3, 2026In BuildKit versions prior to v0.34.1, a malicious client with access to the BuildKit
- CVE-2026-93321Oct 5, 2026Docker: malicious frontend can submit an LLB definition that causes buildkitd to panic
- CVE-2026-93315Oct 5, 2026Docker: When proxy networking with CA injection is enabled, a build can modify its CA
- CVE-2026-93326Oct 5, 2026Docker: build step for a Git source, crafted in a specific way, can bypass some policy
- CVE-2026-93323Oct 5, 2026The Dockerfile frontend loaded the Dockerfile and.dockerignore files of a build context
- CVE-2026-93322Oct 5, 2026Docker: malicious frontend can submit an LLB definition that causes buildkitd to panic
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