CVE-2026-41579
runc is a CLI tool for spawning and running containers according to the OCI specification. In versions prior to 1.3.6, 1.4.0-rc.1, 1.4.0-rc.12, 1.5.0-rc.1, and 1.5.0-rc.1, when setting up the container rootfs, setupPtmx and setupDevSymlinks call os.Remove and os.Symlink with a filepath.Join string which allow an image with /dev as a symlink to trick runc into deleting files called ptmx on the host or creating a hardcoded set of symlinks with specific names and targets in an arbitrary pre-existing host directory. This issue is not exploitable under Docker, because Docker creates a top-level read-only layer that masks any malicious /dev symlink present in the container image — unlike some other Linux container tooling, whose higher-level runtimes built on runc remain exposed to exploitation via a malicious image. This issue has been fixed in versions 1.3.6, 1.4.3 and 1.5.0.
- Score
- CVSS 3.1 3.3 Low
- Status
- Analyzed - security-advisories@github.com
- Published
- 2026-07-01
- Last modified
- 2026-10-25
- Weaknesses
- CWE-61
Affected products
References
- https://github.com/opencontainers/runc/security/advisories/GHSA-xjvp-4fhw-gc47
- https://github.com/opencontainers/runc/commit/864db8042dbb
