CVE-2025-15547

moderate-risk
Published 2026-03-09

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.

Do I need to act?

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0.01% chance of exploitation
EPSS score — low exploit probability
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Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
8
CVSS 8.8/10 High
LOCAL / LOW complexity

Affected Vendors

46
/ 100
moderate-risk
Severity 27/34 · High
Exploitability 0/34 · Minimal
Exposure 19/34 · Moderate