CVE-2026-13377

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

Published Jul 2, 2026 CVSS 4.0 · 4.8 Medium EPSS < 1% KEV · Not listed
Description
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.

Remediation

Vendor Solution

Fireware OS 12.11.9, Fireware OS 2026.2.1, Fireware OS 12.12.1, Fireware OS 12.5.19

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Description 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. 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. 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.
CPEs cpe:2.3:a:watchguard:fireware_os:*:*:*:*:*:*:*:12.0
cpe:2.3:a:watchguard:fireware_os:*:*:*:*:*:*:*:12.5
cpe:2.3:a:watchguard:fireware_os:*:*:*:*:*:*:*:2025.1
cpe:2.3:a:watchguard:fireware_os:*:*:*:*:*:*:*:*
References
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description 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. 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.
Title WatchGuard Firebox Stored Cross-Site-Scripting (XSS) Vulnerability in SIP Proxy Configuration
First Time appeared Watchguard
Watchguard fireware Os
Weaknesses CWE-79
CPEs cpe:2.3:a:watchguard:fireware_os:*:*:*:*:*:*:*:12.0
cpe:2.3:a:watchguard:fireware_os:*:*:*:*:*:*:*:12.5
cpe:2.3:a:watchguard:fireware_os:*:*:*:*:*:*:*:2025.1
Vendors & Products Watchguard
Watchguard fireware Os
References
Metrics cvssV4_0

{'score': 4.8, 'vector': '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'}