CVE-2025-15576
Jail chroot escape via fd exchange with a different jail
Description
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.
INFO
Published Date :
March 9, 2026, 12:16 p.m.
Last Modified :
March 17, 2026, 3:54 p.m.
Remotely Exploit :
No
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | ||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Restrict nullfs mount options.
- Avoid sharing directories between jails.
- Validate jail root configurations.
- Limit unprivileged user access.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-15576.
| URL | Resource |
|---|---|
| https://security.freebsd.org/advisories/FreeBSD-SA-26:04.jail.asc | Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-15576 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-15576
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-15576 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-15576 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Mar. 17, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N Added CPE Configuration OR *cpe:2.3:o:freebsd:freebsd:13.5:p1:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:13.5:p2:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:13.5:p3:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:13.5:p4:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:13.5:p5:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:13.5:p6:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:13.5:p7:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:13.5:p8:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:13.5:-:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:13.5:p9:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:14.3:-:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:14.3:p1:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:14.3:p2:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:14.3:p3:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:14.3:p4:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:14.3:p5:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:14.3:p6:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:14.3:p7:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:14.3:p8:*:*:*:*:*:* Added Reference Type FreeBSD: https://security.freebsd.org/advisories/FreeBSD-SA-26:04.jail.asc Types: Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Mar. 10, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N -
New CVE Received by [email protected]
Mar. 09, 2026
Action Type Old Value New Value Added Description 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. Added CWE CWE-269 Added CWE CWE-488 Added CWE CWE-790 Added Reference https://security.freebsd.org/advisories/FreeBSD-SA-26:04.jail.asc