How severe is CVE-2025-13939?

CVE-2025-13939 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-2025-13939 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-13939?

CVE-2025-13939 affects Watchguard Fireware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-13939?

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

Does CVE-2025-13939 have an EU (EUVD) identifier?

Yes. CVE-2025-13939 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-201300.

When was CVE-2025-13939 published?

CVE-2025-13939 was published on 2025-12-04 and last updated on 2026-06-17.

CVE-2025-13939

CVE-2025-13939 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: 4.8
EPSS exploit prediction: 0% (5th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-201300
Weakness: CWE-79
Affected product: Watchguard Fireware
Published: 2025-12-04
Last modified: 2026-06-17

Description

Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in WatchGuard Fireware OS (Gateway Wireless Controller module) allows Stored XSS.This issue affects Fireware OS 11.7.2 up to and including 11.12.4+541730, 12.0 up to and including 12.11.4, 12.5 up to and including 12.5.13, and 2025.1 up to and including 2025.1.2.

Frequently asked questions

What is CVE-2025-13939?: Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in WatchGuard Fireware OS (Gateway Wireless Controller module) allows Stored XSS.This issue affects Fireware OS 11.7.2 up to and including 11.12.4+541730, 12.0 up to and including 12.11.4, 12.5 up to and including 12.5.13, and 2025.1 up to and including 2025.1.2.
How severe is CVE-2025-13939?: CVE-2025-13939 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-2025-13939 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-13939?: CVE-2025-13939 affects Watchguard Fireware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-13939?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-13939 have an EU (EUVD) identifier?: Yes. CVE-2025-13939 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-201300.
When was CVE-2025-13939 published?: CVE-2025-13939 was published on 2025-12-04 and last updated on 2026-06-17.

References

https://www.watchguard.com/wgrd-psirt/advisory/wgsa-2025-00024

Affected products (1)

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

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