CVE-2026-93323
Description
A flaw was found in BuildKit. A local user with build permissions can trigger a Denial of Service (DoS) by submitting a build context containing an oversized Dockerfile or .dockerignore file. Because the Dockerfile frontend loads these files directly into memory without enforcing a size limit, an excessively large file can exhaust system memory and terminate the build daemon. This termination halts all other active build processes running on the same instance.
Statement
A flaw was found in BuildKit's Dockerfile frontend when processing build contexts. The frontend loads Dockerfile and .dockerignore files directly into memory without enforcing an upper size limit. An authenticated user authorized to submit builds can provide an excessively large Dockerfile or .dockerignore file, forcing the buildkitd daemon to allocate memory proportional to the file size. This unbounded allocation can exhaust host or container memory limits and trigger an out-of-memory termination of the daemon process, crashing active builds running on shared instances.
Mitigation
Enforce file size limits in source control or CI/CD pre-commit hooks to reject Dockerfile and .dockerignore files exceeding 16 MiB prior to build submission, and restrict build execution privileges to trusted users.
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 | 5.5 | N/A | N/A |
| Attack Vector | Local | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | Low | 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:L/UI:N/S:U/C:N/I:N/A:H
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