CVE-2026-103594#

Fireware OS Stack Buffer Overflow in WireGuard Configuration Allows Remote Code Execution

Critical 9.5 CVSS v4.0 › Published 2026-10-27Updated 2026-10-27

Summary #

A stack-based buffer overflow vulnerability in Fireware OS's WireGuard configuration processing allows a remote attacker that has man-in-the-middle TLS-decrypted access between the Firebox and WatchGuard Cloud to create a Denial of Service condition and potentially execute arbitrary code by tampering with a FireCloud Gateway configuration payload.

Product status #

Product	Affected	Not affected
Fireware OS
Default	>= 2026.2, < 2026.4, >= 12.12, < 12.12.4	>= 2026.4, >= 12.12.4

Required Configuration for Exposure #

This vulnerability affects Firebox deployments configured to act as a FireCloud Gateway.

Weakness Type and Impact #

CWECWE-121Stack-based Buffer Overflow
CWECWE-787Out-of-bounds Write
CWECWE-1284Improper Validation of Specified Quantity in Input
CAPECCAPEC-100Overflow Buffers

Exploitation Status #

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

Solution #

Fireware OS 2026.4, Fireware OS 12.12.4

References #

Credits #

WatchGuard AI Security Researchfinder