What is CVE-2026-58093?

CVE-2026-58093 is a high-severity vulnerability in FreeBSD, classified under Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition). CVSS score: 7.0/10. Published 2026-08-26.

How severe is CVE-2026-58093?

High severity. CVSS v3 base score is 7.0 out of 10.

Use After Free in FreeBSD

CVE-2026-58093

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.

Vulnerability class: Race Condition

EPSS: 0.001 (3.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.0 (High). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

Freebsd

Weakness classification (CWE)

References

secteam@freebsd.org (vendor-advisory)

Frequently asked questions

What is CVE-2026-58093?: CVE-2026-58093 is a high-severity vulnerability in FreeBSD, classified under Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition). CVSS score: 7.0/10. Published 2026-08-26.
How severe is CVE-2026-58093?: High severity. CVSS v3 base score is 7.0 out of 10.