Firebox and Fireware OS
CVE-2026-3343: WatchGuard Firebox Reflected Cross-Site-Scripting (XSS) Vulnerability in Fireware Web UI
A reflected cross-site scripting (XSS) vulnerability in the Fireware OS Web UI enabled execution of malicious JavaScript in the context of an authenticated management user's browser when they click on a specially crafted link.
Published
Automatic summary from the vendor's CVE record. We haven't written a full analysis of this vulnerability yet.
Affected and fixed versions
| Product / branch | Fixed in |
|---|---|
| Fireware OS (Default) 2025.1 | 2026.1.2 or later |
| Fireware OS (Default) 12.7 | 12.11.8 or later |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
A reflected cross-site scripting (XSS) vulnerability in the Fireware OS Web UI enabled execution of malicious JavaScript in the context of an authenticated management user's browser when they click on a specially crafted link.
Exploitation
WatchGuard is not aware of any exploitation of this issue in the wild.
Sources
KEV status, EPSS score and vendor data refreshed automatically, last on 13 Oct 2026.