Medium 4.8Published Jul 2, 2026

CVE-2026-13376WatchGuard Firebox Stored Cross-Site-Scripting (XSS) Vulnerability in spamBlocker Module

Updated under an hour ago (Oct 27, 2026, 2:50 AM ET)

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It affects WatchGuard Fireware OS and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Exploited in the last 30 days

Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in WatchGuard Fireware OS spamBlocker module allows Stored XSS. This vulnerability is an additional unmitigated attack path for CVE-2025-1071. This issue affects Fireware OS 12.0 up to and including 12.12, 12.5 up to and including 12.5.18, and 2025.1 up to and including 2026.2.

CVSS: 4.8 MEDIUM (v4.0, CNA)CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
Weakness (CWE): CWE-79
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: WatchGuard
NVD analysis: Modified
Record last updated: Aug 27, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

WatchGuard Fireware OS watchguard:fireware_os (from the name)	from 2025.1 before 2026.2.1; from 12.0 before 12.12.1	CNA record
watchguard fireware watchguard:fireware	from 12.0 before 12.12.1; from 2025.1 before 2026.2.1; from 12.5 through 12.5.18	NVD

References

References

https://psirt.watchguard.com/CVE-2026-13376	vendor-advisory
https://www.watchguard.com/wgrd-psirt/advisory/wgsa-2026-00018	vendor-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.