CVE-2025-62439 Auth bypass in FortiOS
Authenticated users with FSSO knowledge can bypass access controls to reach protected network resources via crafted requests.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-62439?
CVE-2025-62439 is a low-severity authentication bypass vulnerability in Fortinet FortiOS, published on 10 Feb 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
An Improper Verification of Source of a Communication Channel vulnerability [CWE-940] vulnerability in Fortinet FortiOS 7.6.0 through 7.6.4, FortiOS 7.4.0 through 7.4.9, FortiOS 7.2 all versions, FortiOS 7.0 all versions may allow an authenticated user with knowledge of FSSO policy configurations to gain unauthorized access to protected network resources via crafted requests.
Weakness: CWE-940
Which versions are affected by CVE-2025-62439?
How do I fix CVE-2025-62439?
No fix has been published for CVE-2025-62439 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-2025-62439 being exploited?
There is no known exploitation of CVE-2025-62439 in the wild and no public exploit code.
Sources
Also known as GHSA-76xc-486m-c526.