How severe is CVE-2025-4804?

CVE-2025-4804 has a CVSS 4.0 base score of 4.8, rated medium severity.

Is CVE-2025-4804 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (28th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2025-4804?

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

Does CVE-2025-4804 have an EU (EUVD) identifier?

Yes. CVE-2025-4804 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-15550.

When was CVE-2025-4804 published?

CVE-2025-4804 was published on 2025-05-16 and last updated on 2026-06-17.

CVE-2025-4804

CVE-2025-4804 is a medium-severity vulnerability with a CVSS 4.0 base score of 4.8. 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 4.0 base score 4.8)
EPSS exploit prediction: 0% (28th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-15550
Weakness: CWE-79
Published: 2025-05-16
Last modified: 2026-06-17

Description

Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in WatchGuard Fireware OS allows Stored XSS via the spamBlocker module. This vulnerability requires an authenticated administrator session to a locally managed Firebox. This issue affects Fireware OS: from 12.0 through 12.11.1.

Frequently asked questions

What is CVE-2025-4804?: Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in WatchGuard Fireware OS allows Stored XSS via the spamBlocker module. This vulnerability requires an authenticated administrator session to a locally managed Firebox. This issue affects Fireware OS: from 12.0 through 12.11.1.
How severe is CVE-2025-4804?: CVE-2025-4804 has a CVSS 4.0 base score of 4.8, rated medium severity.
Is CVE-2025-4804 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (28th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2025-4804?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-4804 have an EU (EUVD) identifier?: Yes. CVE-2025-4804 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-15550.
When was CVE-2025-4804 published?: CVE-2025-4804 was published on 2025-05-16 and last updated on 2026-06-17.

References

https://www.watchguard.com/wgrd-psirt/advisory/wgsa-2025-00006

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