CVE-2026-101304
HIGH severity · CVSS 7.1 · CWE-273
7.1CVSS HIGH
Summary
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.
Impact & exploitability
Attack vectorLocal
Attack complexityLow
Privileges requiredLow
User interactionNone
Confidentiality impactHigh
Integrity impactHigh
Availability impactNone
Exploit probability (EPSS)0%
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Affected products we track (1)
Recommendation
Apply the vendor fix promptly. Open any affected product above for its exact safe version.
Official patch: https://security.freebsd.org/advisories/FreeBSD-SA-26:66.jail.asc ↗