CVE-2026-86134

Fireware OS Pre-Authentication NULL Pointer Dereference Allows Remote Denial of Service

High 8.7 CVSS v4.0 › Published 2026-09-30Updated 2026-09-30

Summary #

A NULL pointer dereference vulnerability in the WatchGuard Fireware OS authentication process allows a remote, unauthenticated attacker to crash the management daemon by sending a specially request to the login interface, resulting in a denial of service.

Product status #

ProductAffectedNot affected
Fireware OS
Default >= 2026.3, < 2026.3.2, >= 2025.0, < 2026.2.3, >= 12.0, < 12.12.3>= 2026.3.2, >= 2026.2.3, >= 12.12.3
T15/T35 >= 12.0, < 12.5.21>= 12.5.21

Weakness Type and Impact #

Exploitation Status #

WatchGuard is not aware of any exploitation of this vulnerability in the wild.

Solution #

Fireware OS 2026.3.2, Fireware OS 2026.2.3, Fireware OS 12.12.3, Fireware OS 12.5.21

References #

    Credits #

    • WatchGuard AI Security Researchfinder