Dangling Pointer Vulnerability in FreeBSD's TIOCNOTTY Implementation

CVE-2026-5398

What is CVE-2026-5398?

The TIOCNOTTY implementation in FreeBSD presents a critical flaw wherein it fails to properly clear a back-pointer linking the controlling terminal structure to the session of the calling process. This oversight can lead to the retention of a pointer to freed memory. If a malicious process exploits this dangling pointer, it may gain unauthorized root privileges, thereby compromising the system's integrity. System administrators should review affected FreeBSD versions and apply necessary patches to mitigate this risk.

References