An improper certificate validation vulnerability exists in Fortinet FortiOS versions 7.6.0 through 7.6.4, 7.4.0 through 7.4.9, and 7.2.0 through 7.2.13. This flaw may allow a remote, unauthenticated attacker to perform a Man-in-the-Middle (MitM) attack on the SSLVPN web portal's communication with backend destination websites.