Vulnerability Details 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.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.001
EPSS Ranking 3.2%
CVSS Severity
CVSS v3 Score 7.1