CVE-2026-101304 Multiple jail filesystem root escapes
A process in a FreeBSD jail can escape filesystem root restrictions if fdescfs is mounted with the nodup option, allowing unauthorized access to host files.
- 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-2026-101304?
CVE-2026-101304 is a high-severity vulnerability in Freebsd Freebsd, published on 15 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
When fdescfs(4) was mounted in a jail with the "nodup" option, opening /dev/fd/N returned a descriptor that did not inherit FD_RESOLVE_BENEATH or the Capsicum capability rights of descriptor N.
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-2026-101304?
It affects 1 product.
Products include Freebsd Freebsd.
How do I fix CVE-2026-101304?
No fix has been published for CVE-2026-101304 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-101304 being exploited?
There is no known exploitation of CVE-2026-101304 in the wild and no public exploit code.