CopyEscape: Container-to-host arbitrary file write via docker cp (CVE-2026-17106)
Author here. We discovered a vulnerability in docker cp that allows a malicious container to create or overwrite files on the machine running the Docker CLI.
The exploit combines a filesystem race in Docker’s archive creation with unsafe symlink handling during extraction. Depending on the CLI user’s privileges, this can lead to developer-account compromise or root code execution. Docker confirmed that sbx cp was also affected.
Fixed versions:
- Docker Engine/CLI 29.7.2+
- Docker Desktop 4.86.0+
- Docker Sandboxes 0.38.0+
Happy to answer technical questions.
u/ronmasas — 9 days ago