CVE-2026-13376

EUVD-2026-41451
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.
Cross-site Scripting
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
4.8 MEDIUM
NETWORK
LOW
HIGH
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: 6.65%
Affected Products (NVD)
VendorProductVersion
watchguardfireware
12.0 ≤
𝑥
< 12.12.1
watchguardfireware
2025.1 ≤
𝑥
< 2026.2.1
watchguardfireware
12.5 ≤
𝑥
≤ 12.5.18
𝑥
= Vulnerable software versions
Common Weakness Enumeration
References
https://psirt.watchguard.com/CVE-2026-13376
https://www.watchguard.com/wgrd-psirt/advisory/wgsa-2026-00018