CVE-2025-6999 WatchGuard Firebox Authentication Portal Request Smuggling Vulnerability
A remote attacker can perform reflected self-XSS via HTTP request smuggling in the WatchGuard Fireware OS authentication portal, though practical impact is deemed low.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-6999?
CVE-2025-6999 is a medium-severity cross-site scripting vulnerability in WatchGuard Fireware OS, published on 15 Sep 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
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.
Weakness: CWE-444
Which versions are affected by CVE-2025-6999?
How do I fix CVE-2025-6999?
No fix has been published for CVE-2025-6999 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2025-6999 being exploited?
There is no known exploitation of CVE-2025-6999 in the wild and no public exploit code.
Sources
Also known as GHSA-p5qr-qj78-cf65.