CVE-2026-58093

EUVD-2026-66250
The TIOCSCTTY ioctl handler drops the tty lock in order to acquire the process tree lock.  After reacquiring the tty lock, the handler did not revalidate the state of the terminal, and could proceed to link a terminal that was concurrently being destroyed to the calling process' session.

An unprivileged local user can exploit this race condition to escalate privileges.
Race Condition
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
7 HIGH
LOCAL
HIGH
LOW
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Base Score
CVSS 3.x
EPSS Score
Percentile: 0.68%
Affected Products (NVD)
VendorProductVersion
freebsdfreebsd
14.4:p1
freebsdfreebsd
14.4:p2
freebsdfreebsd
14.4:p3
freebsdfreebsd
14.4:p4
freebsdfreebsd
14.4:p5
freebsdfreebsd
14.4:p6
freebsdfreebsd
14.4:p7
freebsdfreebsd
14.4:p8
freebsdfreebsd
15.0:p1
freebsdfreebsd
15.0:p10
freebsdfreebsd
15.0:p11
freebsdfreebsd
15.0:p12
freebsdfreebsd
15.0:p2
freebsdfreebsd
15.0:p3
freebsdfreebsd
15.0:p4
freebsdfreebsd
15.0:p5
freebsdfreebsd
15.0:p6
freebsdfreebsd
15.0:p7
freebsdfreebsd
15.0:p8
freebsdfreebsd
15.0:p9
freebsdfreebsd
15.1:p1
freebsdfreebsd
15.1:p2
𝑥
= Vulnerable software versions