CVE-2026-13377

UNKNOWN 0.0

WatchGuard Firebox Stored Cross-Site-Scripting (XSS) Vulnerability in SIP Proxy Configuration

CVSS Score

0.0

EPSS Score

0.0%

EPSS Percentile

0th

Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in WatchGuard Fireware OS SIP Proxy module allows Stored XSS. This vulnerability is an additional unmitigated attack path for CVE-2025-6947.

CWE	CWE-79
Vendor	watchguard
Product	fireware os
Published	Jul 2, 2026
Last Updated	Aug 10, 2026

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Affected Versions

WatchGuard / Fireware OS

2025.1 < 2026.2.1 12.0 < 12.12.1

WatchGuard / Fireware OS

12.0 < 12.5.19

References

NVD ↗ CVE.org ↗ EPSS Data ↗

psirt.watchguard.com: https://psirt.watchguard.com/CVE-2026-13377 watchguard.com: https://www.watchguard.com/wgrd-psirt/advisory/wgsa-2026-00019

Credits

Simone Paganessi (https://www.linkedin.com/in/simonepaganessi)