---
id: CVE-2026-103594
title: >-
  Fireware OS Stack Buffer Overflow in WireGuard Configuration Allows Remote
  Code Execution
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 Servi…
severity: critical
cvss: 9.5
cvssVector: 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H'
cvssSource: cna
cwe:
  - CWE-121
  - CWE-1284
  - CWE-787
vendor: WatchGuard
product: Fireware OS
affected:
  - fireware_os >= 2026.2 < 2026.4
  - fireware_os >= 12.12 < 12.12.4
published: '2026-10-27'
updated: '2026-10-27'
sourceUpdated: '2026-10-27T15:52:27.758Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-103594'
references:
  - url: 'https://psirt.watchguard.com/CVE-2026-103594'
tags:
  - cve.org
ingestedAt: '2026-10-27T16:11:59.474Z'
---

## Overview

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.

## Affected

- `fireware_os >= 2026.2 < 2026.4`
- `fireware_os >= 12.12 < 12.12.4`

## Remediation

Fireware OS 2026.4, Fireware OS 12.12.4