Vulnerability · Published Sep 15, 2025 · Assigned by WatchGuard

CVE-2025-6999WatchGuard Firebox Authentication Portal Request Smuggling Vulnerability

Medium 6.9

In plain English

A medium-severity security flaw in Fireware OS from WatchGuard. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 39% of all known vulnerabilities).

Severity (CVSS 4.0)6.9Medium

Exploit odds (30 days)0.4%top 60.8% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

Vendor	Product	Versions
WatchGuard	Fireware OS	12.0 – before 12.11.3

Weakness: CWE-444 · 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

References

https://psirt.watchguard.com/CVE-2025-6999 vendor-advisory
https://www.watchguard.com/wgrd-psirt/advisory/wgsa-2025-00014 vendor-advisory