SB2026061687 - UNIX symbolic link following in runc

Description

This security bulletin contains information about 1 vulnerability.

1) UNIX symbolic link following (CVE-ID: CVE-2026-41579)

CWE-ID: CWE-61 - UNIX Symbolic Link (Symlink) Following

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a remote attacker to cause limited host filesystem integrity violations.

The vulnerability exists due to unix symbolic link following in setupPtmx and setupDevSymlinks when setting up the container rootfs from a malicious image with /dev as a symlink. A remote attacker can supply a crafted container image to cause limited host filesystem integrity violations.

The issue can delete host files named ptmx or create a fixed set of symlinks in a pre-existing host directory, and user interaction is required to run the crafted image.

Remediation

Install update from vendor's website.

References

• https://github.com/opencontainers/runc/security/advisories/GHSA-xjvp-4fhw-gc47
• https://github.com/opencontainers/runc/commit/864db8042dbb