CVE-2026-86134 | BDVDB-2026-381239 Detail

WatchGuardFireware OS

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.

Impact#

Per CVSS v4.0: confidentiality impact none, integrity impact none, availability impact high. Attack vector: network.

Weaknesses#

CWE-476 NULL Pointer Dereference

References#

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

Exploit#

No public exploit known

History#

Version 12026-09-30Record published in the CVE List.

Published

Published: 2026-09-30
Last modified: 2026-09-30

Vendor information

Vendor: WatchGuard
Product: Fireware OS

All WatchGuard vulnerabilities

Score

8.7 High

EPSS

less than 1%, Very Low

Estimated chance of exploitation in the next 30 days. EPSS percentile: 34.6.

KEV

Not listed in the CISA Known Exploited Vulnerabilities catalog.

Impact

Memory Corruption

Action

No specific action is recorded in the source data. Check the references for vendor guidance.

Affected Systems

Vulnerable
>= 2026.3 and < 2026.3.2
Fixed
2026.3.2
Vulnerable
>= 2025.0 and < 2026.2.3
Fixed
2026.2.3
Vulnerable
>= 12.0 and < 12.12.3
Fixed
12.12.3
Vulnerable
>= 12.0 and < 12.5.21
Fixed
12.5.21

Scoring System

CVSS v4.0

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

Metric breakdown
Attack Vector	Network
Attack Complexity	Low
Attack Requirements	None
Privileges Required	None
User Interaction	None
Vulnerable System Confidentiality	None
Vulnerable System Integrity	None
Vulnerable System Availability	High
Subsequent System Confidentiality	None
Subsequent System Integrity	None
Subsequent System Availability	None

CVSS v3.1

Not available

CVSS v3.0

Not available

CVSS v2

Not available

Source: CVE List v5 (record); CISA KEV (kev, action); FIRST EPSS (epss).