CVE-2026-3343

WatchGuard Firebox Reflected Cross-Site-Scripting (XSS) Vulnerability in Fireware Web UI

CVSS 5.1 MEDIUMEPSS 0.2%CWE-79

Vexday Risk Score

13Low

SSVC decision (CISA)

Track

No exploitation signal → monitor

CVSS 5.1EPSS 0.2%KEV nãoPoC —Nuclei —Metasploit —Patch —

Lifecycle

03 Mar 2026Published on NVD

Recommendation: Monitor — no exploitation signal at the moment.

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. This vulnerability affects Fireware OS 12.7 up to and including 12.11.7 and 2025.1 up to and including 2026.1.1.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

Affected products

WatchGuard · Fireware OS

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References

https://www.watchguard.com/wgrd-psirt/advisory/wgsa-2026-00004