Description
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.
CVSS Metrics
- Vector
- CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- Attack Vector
- local
- Complexity
- low
- Privileges
- low
- User Action
- none
- Scope
- changed
- Confidentiality
- high
- Integrity
- high
- Availability
- high
- Weaknesses
- CWE-269
Metadata
- Primary Vendor
- FREEBSD
- Published
- 3/9/2026
- Last Modified
- 3/17/2026
- Source
- NIST NVD
- Note: Verify all details with official vendor sources before applying patches.
Affected Products
freebsd : freebsdfreebsd : freebsdfreebsd : freebsdfreebsd : freebsdfreebsd : freebsdfreebsd : freebsdfreebsd : freebsdfreebsd : freebsdfreebsd : freebsdfreebsd : freebsdfreebsd : freebsdfreebsd : freebsdfreebsd : freebsdfreebsd : freebsdfreebsd : freebsdfreebsd : freebsdfreebsd : freebsd
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