UNIX symbolic link following in runc - CVE-2026-41579
Published: June 16, 2026
Vulnerability identifier: #VU134680
CSH Severity: Low
CVSS v4.0: 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
CVE-ID: CVE-2026-41579
CWE-ID: CWE-61
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Open Container Initiative
Affected software:
runc
runc
Detailed vulnerability description
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.
How to mitigate CVE-2026-41579
Install security update from vendor's website.