CVE-2026-126247 Memory corruption in FortiAuthenticator
An authenticated privileged attacker can exploit a format string flaw via HTTP requests to execute unauthorized code on FortiAuthenticator.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- 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-2026-126247?
CVE-2026-126247 is a high-severity memory corruption vulnerability in Fortinet FortiAuthenticator, published on 11 Nov 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Official description
A use of externally-controlled format string vulnerability in Fortinet FortiAuthenticator 8.0.0 through 8.0.3, FortiAuthenticator 6.6.0 through 6.6.10 may allow an authenticated privileged attacker to execute unauthorized code or commands via http requests.
Weakness: CWE-134
Which versions are affected by CVE-2026-126247?
An affected version is exposed as installed. No special setting or call is needed.
How do I fix CVE-2026-126247?
No fix has been published for CVE-2026-126247 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-126247 being exploited?
There is no known exploitation of CVE-2026-126247 in the wild and no public exploit code.
Sources
Also known as GHSA-9r63-2p2h-xm89.