CVE-2026-93315
Description
A flaw was found in BuildKit. When proxy networking with Certificate Authority (CA) injection is enabled, a build can modify its CA certificate bundle before cleanup operations execute. A local user running a build can exploit this issue to cause the cleanup process to hang, resulting in a Denial of Service (DoS), or trigger file modifications outside the build's intended root filesystem (rootfs).
Statement
A race condition flaw was found in BuildKit when proxy networking with Certificate Authority (CA) injection is enabled. BuildKit does not ensure atomicity between validating and cleaning up injected CA bundles. A local user executing a build can manipulate the CA bundle path or replace it with a symlink before cleanup runs. When the buildkitd daemon executes post-build cleanup, operations can hang indefinitely—causing a denial of service—or traverse outside the container rootfs, resulting in unauthorized file modification or deletion on the underlying host.
Mitigation
Disable proxy networking with CA injection in BuildKit daemon configurations. Alternatively, isolate builds into ephemeral, single-tenant container runners and restrict build submission access 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 | 6.4 | N/A | N/A |
| Attack Vector | Local | N/A | N/A |
| Attack Complexity | High | N/A | N/A |
| Privileges Required | Low | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Changed | N/A | N/A |
| Confidentiality | None | N/A | N/A |
| Integrity Impact | Low | N/A | N/A |
| Availability Impact | High | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:H
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
