How severe is CVE-2026-3343?

CVE-2026-3343 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2026-3343 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (9th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-3343?

CVE-2026-3343 affects Watchguard Fireware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-3343?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-3343 have an EU (EUVD) identifier?

Yes. CVE-2026-3343 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-9289.

When was CVE-2026-3343 published?

CVE-2026-3343 was published on 2026-03-03 and last updated on 2026-06-17.

CVE-2026-3343

CVE-2026-3343 is a medium-severity vulnerability in Watchguard Fireware with a CVSS 3.x base score of 6.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: Medium (CVSS 3.x base score 6.1)
CVSS v4: 5.1
EPSS exploit prediction: 0% (9th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-9289
Weakness: CWE-79
Affected product: Watchguard Fireware
Published: 2026-03-03
Last modified: 2026-06-17

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

Frequently asked questions

What is 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.
How severe is CVE-2026-3343?: CVE-2026-3343 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2026-3343 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (9th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-3343?: CVE-2026-3343 affects Watchguard Fireware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-3343?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-3343 have an EU (EUVD) identifier?: Yes. CVE-2026-3343 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-9289.
When was CVE-2026-3343 published?: CVE-2026-3343 was published on 2026-03-03 and last updated on 2026-06-17.

References

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

Affected products (1)

cpe:2.3:o:watchguard:fireware:*:*:*:*:*:*:*:*

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