CVE-2026-101305 Multiple jail filesystem root escapes

High 8.8 Published 15 Oct 2026 Updated 16 Oct 2026

A jailed process can escape the filesystem root restriction by exploiting a flaw in renameat(2) and fchdir(2) handling.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-101305?

CVE-2026-101305 is a high-severity path traversal vulnerability in Freebsd Freebsd, published on 15 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

renameat(2) did not enforce FD_RESOLVE_BENEATH on its directory arguments. A jailed process could rename a directory relative to a restricted descriptor, then escape the jail root via fchdir(2). This requires the directory to reside on a filesystem that is also reachable from the jail's root.

A process in a jail that has received a directory file descriptor from another jail can use these techniques to escape the jail's filesystem root restriction.

Weakness: CWE-273

Which versions are affected by CVE-2026-101305?

It affects 1 product.

Products include Freebsd Freebsd.

How do I fix CVE-2026-101305?

No fix has been published for CVE-2026-101305 yet. Limit exposure of the affected software until one is available.

Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.

Is CVE-2026-101305 being exploited?

There is no known exploitation of CVE-2026-101305 in the wild and no public exploit code.

All Freebsd Freebsd vulnerabilities

Sources

Also known as GHSA-crp4-cfvg-6vr3.