CVE-2025-15547: Freebsd

High severity, CVSS 8.8. EPSS: 0.1% chance of exploitation in the next 30 days.

By default, jailed processes cannot mount filesystems, including nullfs(4). However, the allow.mount.nullfs option enables mounting nullfs filesystems, subject to privilege checks. If a privileged user within a jail is able to nullfs-mount directories, a limitation of the kernel's path lookup logic allows that user to escape the jail's chroot, yielding access to the full filesystem of the host or parent jail. In a jail configured to allow nullfs(4) mounts from within the jail, the jailed root user can escape the jail's filesystem root.

Affected products

• Freebsd Freebsd: version 13.5 only; version 14.3 only

Published 2026-03-09. Last modified 2026-06-17.