Description
In BuildKit versions prior to v0.34.1, a malicious client with access to the BuildKit control APIs can submit a build request that sets an extended attribute on a file outside the BuildKit state directory. Extended attributes in the trusted. or security. namespaces may also be set, potentially giving a program on the host elevated privileges. This issue affects build services that accept build requests from untrusted users. The issue is fixed in v0.34.1.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Moby | BuildKit | < 0.34.1 | 0.34.1 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | docker.io +1 | No fix yet | — |
| Ubuntu 26.04 LTS | docker.io +1 | No fix yet | — |
Show 5 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 24.04 LTS | docker.io +1 | No fix yet | — |
| Ubuntu Pro 22.04 LTS | docker.io +1 | No fix yet | — |
| Ubuntu Pro 20.04 LTS | docker.io +1 | No fix yet | — |
| Ubuntu Pro 18.04 LTS | docker.io | No fix yet | — |
| Ubuntu Pro 16.04 LTS | docker.io | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat Hardened Images 1 | podman +4 | 5:6.1.4-1.3.hum1 | RHSA-2026:95611 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | moby-engine +2 | No fix yet | — |
Advisories 2
- RHSA-2026:95611 Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update Red Hat Security Advisories (RHSA) · Nov 13, 2026
- WID-SEC-2026-4338 BuildKit: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 10, 2026