What is the CVSS score of CVE-2025-15576?

CVE-2025-15576 has a CVSS 3.1 base score of 7.5 (High). CVSS vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N. EPSS exploitation probability: 0.0%.

Which versions of Freebsd are affected by CVE-2025-15576?

This vulnerability allows jailed processes on FreeBSD systems to potentially bypass filesystem isolation through nullfs mount configurations, creating unauthorized access to shared directories.

How to fix or mitigate CVE-2025-15576?

Within 24 hours: Audit all FreeBSD systems for nullfs mount configurations between sibling jails and document current jail architecture. Within 7 days: Implement filesystem isolation controls by removing unnecessary nullfs mounts between separate jail root directories and validate jail separation. Within 30 days: Develop and deploy a jail configuration hardening policy, implement monitoring for unauthorized cross-jail filesystem access attempts, and establish a vulnerability tracking process for FreeBSD-specific issues pending patch availability.

Freebsd CVE-2025-15576

HIGH

Improper Privilege Management (CWE-269)

2026-03-09 secteam@freebsd.org

Privilege Escalation Microsoft Freebsd

7.5

CVSS 3.1

CVSS VectorNVD

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N

Attack Vector

Local

Attack Complexity

High

Privileges Required

Low

User Interaction

None

Scope

Changed

Confidentiality

High

Integrity

High

Availability

None

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 21:56 vuln.today

CVE Published

Mar 09, 2026 - 12:16 nvd

HIGH 7.5

DescriptionNVD

If two sibling jails are restricted to separate filesystem trees, which is to say that neither of the two jail root directories is an ancestor of the other, jailed processes may nonetheless be able to access a shared directory via a nullfs mount, if the administrator has configured one.

In this case, cooperating processes in the two jails may establish a connection using a unix domain socket and exchange directory descriptors with each other.

When performing a filesystem name lookup, at each step of the lookup, the kernel checks whether the lookup would descend below the jail root of the current process. If the jail root directory is not encountered, the lookup continues.

In a configuration where processes in two different jails are able to exchange file descriptors using a unix domain socket, it is possible for a jailed process to receive a directory for a descriptor that is below that process' jail root. This enables full filesystem access for a jailed process, breaking the chroot.

Note that the system administrator is still responsible for ensuring that an unprivileged user on the jail host is not able to pass directory descriptors to a jailed process, even in a patched kernel.

AnalysisAI

Technical ContextAI

Classified as CWE-269 (Improper Privilege Management). If two sibling jails are restricted to separate filesystem trees, which is to say that neither of the two jail root directories is an ancestor of the other, jailed processes may nonetheless be able to access a shared directory via a nullfs mount, if the administrator has configured one.

In this case, cooperating processes in the two jails may establish a connection using a unix domain socket and exchange directory descriptors with each other.

When performing a filesystem name lookup, at each s