NULL Pointer Dereference Vulnerability in WatchGuard Fireware OS
CVE-2026-86134

8.7HIGH

Key Information:

Vendor

Watchguard

Status
Fireware Os
Vendor
CVE Published:
30 September 2026

Badges

👾 Exploit Exists

What is CVE-2026-86134?

A NULL pointer dereference vulnerability in the authentication process of WatchGuard Fireware OS can be exploited by a remote, unauthenticated attacker. By sending a specially crafted request to the login interface, the attacker could crash the management daemon, leading to a Denial of Service condition. This issue underscores the importance of securing authentication mechanisms to prevent potential service disruptions.

Affected Version(s)

Fireware OS Default 2026.3 < 2026.3.2

Fireware OS Default 2025.0 < 2026.2.3

Fireware OS Default 12.0 < 12.12.3

References

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

CVSS V4

Score:
8.7
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

WatchGuard AI Security Research
.