6.1

CVE-2026-3343: WatchGuard Firebox Reflected Cross-Site-Scripting (XSS) Vulnerability in Fireware Web UI

Modified
Published 03-03-2026Last modified 10-08-2026

Vulnerability summary

CVE-2026-3343 is a medium (CVSS 6.1) Cross-site Scripting vulnerability in watchguard fireware. EPSS estimates a 0.34% chance of exploitation in the next 30 days, higher than 26.5% of scored vulnerabilities.

Overall risk
24/100
0100
Low · default modelHow is this calculated?
CVSS score
6.1/10
010
Medium · v3.1 (NVD)
EPSS score
0.34%
0%100%
Low · +0.14 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 03-03-2026
    PublishedVulnerability first disclosed.
  2. 10-08-2026
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

3 scores · 2 sources · 2 versions

EPSS trend

Probability

0.34%

Chance of exploitation in the next 30 days

Percentile

27%

Versus all other CVEs

30-day change

Increase +0.14 pp

From 0.21% on 22-09-2026

22-09-202622-10-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Watchguard2 products
  • fireware≥ 12.7, < 12.11.8 | ≥ 2025.1, < 2026.1.2
  • fireware os≥ 2025.1, < 2026.1.2 | ≥ 12.7, < 12.11.8

1 vendor · 2 products

References

2 links