Improper access control in FreeBSD - CVE-2026-101304
Published: September 30, 2026
Vulnerability identifier: #VU152946
CSH Severity: Low
CVSS v4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-101304
CWE-ID: CWE-284
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to escape the jail's filesystem root restriction.
The vulnerability exists due to improper access control in fdescfs(4) when opening /dev/fd/N with fdescfs mounted using the nodup option. A local user can open /dev/fd/N to escape the jail's filesystem root restriction.
Exploitation requires a directory file descriptor received from another jail.
Affected software
FreeBSD
How to mitigate CVE-2026-101304
Install security update from vendor's website.