Vulnerability Report

CVE-2026-3343

Title: Reflected XSS in WatchGuard Fireware OS Web UI

XSS

Proof Of Concept

No public PoC currently indexed for CVE-2026-3343.

CWE Category CWE-79

Published Date Mar 03, 2026

Modified Date Mar 04, 2026

Exploit Status Not Found

Score 5.1 CVSS v4.0

Exploit Probability (EPSS)

0.20%

Vulnerability Summary

CVE-2026-3343: 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.

Impacted Vendors

watchguard 36

Reference Links

https://www.watchguard.com/wgrd-psirt/advisory/wgsa-2026-0004

CVSS v4.0

Source Entity 5d1c2695-1a31-4499-88ae-e847036fd7e3

Severity MEDIUM

5.1

Attack Vector

NETWORK

Complexity

LOW

Privileges

N/A

Interaction

ACTIVE

Confidentiality

N/A

Integrity

N/A

Availability

N/A

Scope

N/A

RAW VECTOR

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS v3.1

Source Entity [email protected]

Severity MEDIUM

6.1

Attack Vector

NETWORK

Complexity

LOW

Privileges

N/A

Interaction

REQUIRED

Confidentiality

N/A

Integrity

N/A

Availability

N/A

Scope

CHANGED

RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Associated Attack Patterns (CAPEC)

Total: Patterns