Description
The Dockerfile frontend loaded the Dockerfile and .dockerignore files of a build context into memory without a size limit. A build context containing an oversized file could make buildkitd allocate memory proportional to that file, potentially exhausting memory and terminating the daemon, which interrupts other builds on the same instance. Fixed by rejecting such files above 16 MiB.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| moby | BuildKit | ≤ 0.33.0 | — |
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 | — |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | docker-buildx | No fix yet | — |
| Azure Linux 3 | moby-engine | 25.0.18-1 | — |
Advisories 1
- WID-SEC-2026-3741 BuildKit: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 25, 2026