CVE-2025-52565

A flaw was found in runc. CVE-2025-52565 is very similar in concept and application toCVE-2025-31133, except that it exploits a flaw in /dev/console bind-mounts. When creating the /dev/console bind-mount (to /dev/pts/$n), if an attacker replaces /dev/pts/$n with a symlink then runc will bind-mount the symlink target over /dev/console.

Red Hat considers this as an Important flaw since the impact is limited to local attack with minimal privileges in order to jeopardize the environment.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Potential mitigations for this issue include:

• Using user namespaces, with the host root user not mapped into the container's namespace. procfs file permissions are managed using Unix DAC and thus user namespaces stop a container process from being able to write to them.
• Not running as a root user in the container (this includes disabling setuid binaries with noNewPrivileges). As above, procfs file permissions are managed using Unix DAC and thus non-root users cannot write to them.
• The default SELinux policy should mitigate this issue, as the /dev/console bind-mount does not re-label the mount and so the container process should not be able to write to unsafe procfs files. However, CVE-2025-52881 allows an attacker to bypass LSM labels, and so this mitigation is not helpful when considered in combination with CVE-2025-52881.
• The default AppArmor profile used by most runtimes will NOT help mitigate this issue, as /dev/console access is permitted. You could create a custom profile that blocks access to /dev/console, but such a profile might break regular containers. In addition, CVE-2025-52881 allows an attacker to bypass LSM labels, and so that mitigation is not helpful when considered in combination with CVE-2025-52881.