Root Privilege Escalation via Dangling Terminal Pointer in FreeBSD TIOCNOTTY
CVE-2026-5398 Published on April 22, 2026

Kernel use-after-free bug in the TIOCNOTTY handler
The implementation of TIOCNOTTY failed to clear a back-pointer from the structure representing the controlling terminal to the calling process' session. If the invoking process then exits, the terminal structure may end up containing a pointer to freed memory. A malicious process can abuse the dangling pointer to grant itself root privileges.

Vendor Advisory NVD

Vulnerability Analysis

CVE-2026-5398 is exploitable with local system access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to be very high.

Attack Vector:
LOCAL
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
HIGH
Availability Impact:
HIGH

Weakness Type

What is a Dangling pointer Vulnerability?

Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code.

CVE-2026-5398 has been classified to as a Dangling pointer vulnerability or weakness.


Products Associated with CVE-2026-5398

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FreeBSD
 

Affected Versions

FreeBSD: