CVE-2026-93321
Description
A flaw was found in BuildKit. A malicious build frontend can submit a crafted low-level builder (LLB) definition that triggers an unexpected panic in the BuildKit daemon. This issue leads to a Denial of Service (DoS), causing the daemon process to crash and interrupting all active builds running on the host.
Statement
A denial of service flaw was found in BuildKit's low-level builder (LLB) definition processing subsystem. The buildkitd daemon fails to properly validate input parameters and array indices within submitted LLB definitions. A malicious build frontend can supply a crafted LLB definition referencing invalid elements or operations, triggering an unhandled Go runtime panic. This panic abruptly terminates the buildkitd daemon process, crashing all concurrent and active build operations running on the shared host or container instance.
Mitigation
Avoid using custom or untrusted BuildKit frontends, and restrict build submission access to verified users. Isolate build daemon instances per tenant to prevent cross-tenant build interruption.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.2 | N/A | N/A |
| Attack Vector | Local | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | None | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | None | N/A | N/A |
| Integrity Impact | None | N/A | N/A |
| Availability Impact | High | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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