CVE-2026-101304

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.

Score

CVSS 3.1 7.1 High

Status

Modified - secteam@freebsd.org

Published

2026-10-15

Last modified

2026-10-20

Weaknesses

CWE-273

Affected products

• Freebsd (Freebsd)

References

• https://security.freebsd.org/advisories/FreeBSD-SA-26:66.jail.asc