CVE-2025-6999

WatchGuard Firebox Authentication Portal Request Smuggling Vulnerability

Published Sep 15, 2025 CVSS 4.0 · 6.9 Medium EPSS < 1% KEV · Not listed
Description
An HTTP Request Smuggling [CWE-444] vulnerability in the Authentication portal of WatchGuard Fireware OS allows a remote attacker to evade request parameter sanitation and perform a reflected self-Cross-Site Scripting (XSS) attack.

WatchGuard does not believe there is a practical exploit chain with a meaningful security impact for this vulnerability.

Remediation

Vendor Solution

Fireware OS 12.11.3

Tracking

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Advisories

Source ID Title
EUVD EUVD EUVD-2025-29270 An HTTP Request Smuggling [CWE-444] vulnerability in the Authentication portal of WatchGuard Fireware OS allows a remote attacker to evade request parameter sanitation and perform a reflected self-Cross-Site Scripting (XSS) attack.This issue affects Fireware OS: from 12.0 through 12.11.2.
History
Type Values Removed Values Added
Description An HTTP Request Smuggling [CWE-444] vulnerability in the Authentication portal of WatchGuard Fireware OS allows a remote attacker to evade request parameter sanitation and perform a reflected self-Cross-Site Scripting (XSS) attack.This issue affects Fireware OS: from 12.0 through 12.11.2. An HTTP Request Smuggling [CWE-444] vulnerability in the Authentication portal of WatchGuard Fireware OS allows a remote attacker to evade request parameter sanitation and perform a reflected self-Cross-Site Scripting (XSS) attack. WatchGuard does not believe there is a practical exploit chain with a meaningful security impact for this vulnerability.
First Time appeared Watchguard fireware Os
CPEs cpe:2.3:a:watchguard:fireware_os:*:*:*:*:*:*:*:*
Vendors & Products Watchguard fireware Os
References
Type Values Removed Values Added
First Time appeared Watchguard
Watchguard fireware
Vendors & Products Watchguard
Watchguard fireware
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 An HTTP Request Smuggling [CWE-444] vulnerability in the Authentication portal of WatchGuard Fireware OS allows a remote attacker to evade request parameter sanitation and perform a reflected self-Cross-Site Scripting (XSS) attack.This issue affects Fireware OS: from 12.0 through 12.11.2.
Title WatchGuard Firebox Authentication Portal Request Smuggling Vulnerability
Weaknesses CWE-444
References
Metrics cvssV4_0

{'score': 6.9, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
WatchGuard
Published
Updated
Aug 10, 2026, 3:26 PM
Reserved
Jul 2, 2025, 12:11 AM
Status
Deferred
Published
Sep 15, 2025, 10:15 PM
Modified
Aug 10, 2026, 4:19 PM