Privilege Escalation Vulnerability in FreeBSD Terminal Handling

CVE-2026-58093

What is CVE-2026-58093?

A vulnerability exists within the TIOCSCTTY ioctl handler in FreeBSD that allows an unprivileged local user to exploit a race condition. The handler improperly manages the tty lock while trying to acquire the process tree lock. This flaw enables the potential re-linking of a terminal, which is being destroyed, to the user's process session. This can lead to unauthorized privilege escalation, posing a significant risk to system security.

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