Improper Authentication in FortiOS - CVE-2026-121530
Published: November 11, 2026
Vulnerability identifier: #VU165239
CSH Severity: Low
CVSS v4: 7.5 [CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-121530
CWE-ID: CWE-287
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote privileged user to execute arbitrary code.
The vulnerability exists due to improper authentication in Two-Factor-Authentication. A remote authenticated attacker with at least read-only permission can log in to the FortiOS GUI with an invalid token after entering a valid username and password, in scenarios where the RADIUS server returns an additional "Access-Challenge" response following an invalid TFA token.
Affected software
FortiOS
How to mitigate CVE-2026-121530
Install update from vendor's website.
FortiOS - update to 7.6.7