CVE-2026-126251 Auth bypass in FortiAuthenticator
Attackers can bypass authentication and gain unauthorized access to FortiAuthenticator; Fortinet customers should update.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Harmful if only installed
- No
- Needs a specific call
- No
- Fix
- None listed
What is CVE-2026-126251?
CVE-2026-126251 is a critical authentication bypass vulnerability in Fortinet FortiAuthenticator, published on 11 Nov 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A incorrect authorization vulnerability in Fortinet FortiAuthenticator 8.0.0 through 8.0.3, FortiAuthenticator 6.6.0 through 6.6.10 may allow an attacker to bypass authentication and gain unauthorized access.
Weakness: CWE-863
Which versions are affected by CVE-2026-126251?
An affected version is exposed as installed. No special setting or call is needed.
How do I fix CVE-2026-126251?
No fix has been published for CVE-2026-126251 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-126251 being exploited?
There is no known exploitation of CVE-2026-126251 in the wild and no public exploit code.
Sources
Also known as GHSA-2v4p-6vfq-jfpp.