CVE-2026-86134 WatchGuard Fireware OS - Denial of Service

WatchGuard Fireware OS contains a null pointer dereference caused by improper handling in the authentication process, letting remote unauthenticated attackers crash the management daemon, exploit requires sending a specially crafted request to the login interface.

CVSS base score 7.5 /10
High
CISA KEV
Not listed
Public exploit
None known
Authentication
Not required
EPSS
0.38% chance of exploitation in 30 days
View the NVD record ↗

Details

Type
Denial of Service
Impact
Denial Of Service
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
30 September 2026
Updated
15 October 2026
Weakness
CWE-476

Vendor fix

Update to the latest version of WatchGuard Fireware OS.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

References

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