CVE-2026-93315 PUBLISHED

BuildKit proxy CA cleanup can be disrupted by build steps

Assigner: Docker
Reserved: 17.09.2026 Published: 05.10.2026 Updated: 06.10.2026

When proxy networking with CA injection is enabled, a build can modify its CA bundle before cleanup. This may cause cleanup to block, operate outside the build rootfs, or fail without failing the build.

Metrics

CVSS 4.0

CVSS Vector: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:L/VA:H/SC:N/SI:L/SA:N
CVSS Score: 5.8

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Local	Confidentiality	None	Confidentiality	None
Attack Complexity	Low	Integrity	Low	Integrity	Low
Attack Requirements	Present	Availability	High	Availability	None
Privileges Required	Low
User Interaction	None

CVSS 4.0

Product Status

Vendor	moby
Product	BuildKit
Versions	Default: unaffected affected from 0.31.0 to 0.33.1 (excl.)

Workarounds

Avoid using build sources from untrusted locations. Only builds enabling proxy networking for exec steps (either via BuildKitd TOML config or Buildx Rego policy) are affected.

Credits

Zhenchen Wang (Institute of Software, Chinese Academy of Sciences), Shuo Huai, Songlin Zhu, Weijie Liu, and Yan Jia (Nankai University) finder

References

Problem Types

CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition CWE