Is CVE-2026-3343 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-3343 being exploited in the wild.

How severe is CVE-2026-3343?

Medium severity, with a CVSS score of 6.1, published 3 March 2026.

Which products and versions are affected?

Watchguard Fireware OS 2025.1 to 2026.1.1, 12.7 to 12.11.7.

Is there a fix for CVE-2026-3343?

A patch was published on 2026-03-03: Patches released: Fireware OS 2026.1.2 and 12.11.8 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-3343 attacked?

It is attacked over the network.

Am I affected by CVE-2026-3343?

Check whether you run Watchguard Fireware OS at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-3343: WatchGuard Fireware OS reflected XSS in Web UI

CVE-2026-3343 · Severity: medium · CVSS 6.1 · Published 2026-03-03

WatchGuard Fireware OS is a firewall platform used to secure corporate networks. A reflected cross-site scripting (XSS) vulnerability in the Web UI management interface allows an attacker to inject malicious JavaScript code that executes in an administrator's browser when they click a specially crafted link. This could lead to unauthorized configuration changes, credential theft, or system compromise under the attacker's control.

Technologies: Watchguard Fireware OS. Vendors: Watchguard.

Quick answers

Is CVE-2026-3343 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-3343 being exploited in the wild.
How severe is CVE-2026-3343?: Medium severity, with a CVSS score of 6.1, published 3 March 2026.
Which products and versions are affected?: Watchguard Fireware OS 2025.1 to 2026.1.1, 12.7 to 12.11.7.
Is there a fix for CVE-2026-3343?: A patch was published on 2026-03-03: Patches released: Fireware OS 2026.1.2 and 12.11.8 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-3343 attacked?: It is attacked over the network.
Am I affected by CVE-2026-3343?: Check whether you run Watchguard Fireware OS at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

This is a reflected cross-site scripting (CWE-79) vulnerability in the Fireware OS Web UI that fails to properly neutralize user-supplied input during web page generation. The vulnerability requires an authenticated management user to click on a specially crafted malicious link, but does not require prior authentication from the attacker. Once clicked, arbitrary JavaScript executes in the context of the authenticated user's browser session, potentially allowing session hijacking, admin action abuse, or credential exfiltration. Patches are available: Fireware OS 2026.1.2 and 12.11.8 or later resolve this issue.

Affected products

WatchGuard Fireware OS 2025.1 to 2026.1.1, 12.7 to 12.11.7

Timeline

2026-03-03: disclosed
2026-03-03: patched: Patches released: Fireware OS 2026.1.2 and 12.11.8

References

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