CVE-2026-86134

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

State: Published
Severity: 8.7 High
Published: Sep 30, 2026
Updated: Sep 30, 2026
Reserved: Sep 5, 2026

Description

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.

Scores

CVSS	Score	Vector	Source
4.0	8.7 High	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N	WatchGuard

Weaknesses

CWE-476

Affected Products

Product	Versions
Fireware OSWatchGuard	2026.3 to before 2026.3.2Affected 2025.0 to before 2026.2.3Affected 12.0 to before 12.12.3Affected
Fireware OSWatchGuard	12.0 to before 12.5.21Affected

References

https://psirt.watchguard.com/CVE-2026-86134vendor-advisory

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