CVE-2025-15576 Jail chroot escape via fd exchange with a different jail
A jailed process can escape its chroot and access the full filesystem by exchanging directory descriptors with a sibling jail via a Unix domain socket.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-15576?
CVE-2025-15576 is a high-severity vulnerability in Freebsd Freebsd, published on 9 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Which versions are affected by CVE-2025-15576?
It affects 1 product.
Products include Freebsd Freebsd.
How do I fix CVE-2025-15576?
No fix has been published for CVE-2025-15576 yet. Limit exposure of the affected software until one is available.
Is CVE-2025-15576 being exploited?
There is no known exploitation of CVE-2025-15576 in the wild and no public exploit code.
Other vulnerabilities in Freebsd Freebsd
Sources
Also known as GHSA-42fj-xxgc-m676.