Docker: `PUT /containers/{id}/archive` executes container binary on the host

CVE-2026-41567

What is CVE-2026-41567?

Moby is an open source container framework. In versions prior to 29.5.1 and in moby/moby v2 prior to v2.0.0-beta.14, when a compressed archive is uploaded to a container via PUT /containers/{id}/archive or piped through docker cp -, the daemon resolves decompression binaries (such as xz or unpigz) from the container's filesystem rather than the host's due to incorrect ordering of operations. A malicious container image containing a trojanized decompression binary can achieve arbitrary code execution with full daemon privileges, including host root UID and unrestricted capabilities, when a user uploads a compressed (xz or gzip) archive into that container. This issue is fixed in Docker Engine 29.5.1 and moby/moby v2.0.0-beta.14. Workarounds include only running containers from trusted images, using authorization plugins to restrict access to the PUT /containers/{id}/archive endpoint, and avoiding piping compressed archives into containers created from untrusted images

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