CVE-2026-3343Network attack vector

Browser script execution via crafted management link

Published Mar 3, 2026 · Updated Mar 3, 2026

Reflected XSS in WatchGuard Fireware OS 12.7 through 12.11.7 and 2025.1 through 2026.1.1 allows attackers to run browser scripts. WatchGuard has not disclosed the affected Web UI endpoint, parameter, or output-encoding operation that reflects the crafted input. The script runs in the management origin after an authenticated management user clicks the link, permitting limited reading or alteration of Web UI data.

CVSS severity5.1
Medium
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reflected XSS in WatchGuard Fireware OS 12.7 through 12.11.7 and 2025.1 through 2026.1.1 allows attackers to run browser scripts. WatchGuard has not disclosed the affected Web UI endpoint, parameter, or output-encoding operation that reflects the crafted input. The script runs in the management origin after an authenticated management user clicks the link, permitting limited reading or alteration of Web UI data.

The record

CVE
CVE-2026-3343
Published
Mar 3, 2026
Updated
Mar 3, 2026
Vendor
WatchGuard Technologies
Product
Fireware OS
Classifications
CWE-79, T1204.001, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 3, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 3, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=12.7 <=12.11.7
  2. Affected versionversion=2025.1 <=2026.1.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

WatchGuard Technologies · Fireware OSversion=12.7 <=12.11.7; version=2025.1 <=2026.1.1

Published CVSS scores

6.1NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
5.1WatchGuard Technologies, Inc.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

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1204.001Malicious Link
T1203Exploitation for Client Execution

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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