Privilege escalation in FreeBSD

CVE-2025-15547

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.

Vulnerability class: Privilege Escalation

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.001 (1.2th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 1st percentile — 1.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-15547: held from 0.001 to 0.001.

EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: 0.000

Affected products

  • FreeBSD — versions 14.3, 13.5, 14.3-RELEASE

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-15547?
CVE-2025-15547 is a high-severity vulnerability in FreeBSD, classified under Improper Privilege Management. CVSS score: 8.8/10. Published 2026-03-09.
How severe is CVE-2025-15547?
High severity. CVSS v3 base score is 8.8 out of 10.