CVE-2021-26103: Fortinet FortiOS

High severity, CVSS 8.8. EPSS: 0.4% chance of exploitation in the next 30 days.

An insufficient verification of data authenticity vulnerability (CWE-345) in the user interface of FortiProxy verison 2.0.3 and below, 1.2.11 and below and FortiGate verison 7.0.0, 6.4.6 and below, 6.2.9 and below of SSL VPN portal may allow a remote, unauthenticated attacker to conduct a cross-site request forgery (CSRF) attack . Only SSL VPN in web mode or full mode are impacted by this vulnerability.

Affected products

• Fortinet FortiOS: from 5.6.0, up to and including 5.6.14; from 6.0.0, up to and including 6.0.13; from 6.2.0, up to and including 6.2.9; from 6.4.0, up to and including 6.4.6; version 7.0.0 only
• Fortinet FortiProxy: from 1.2.0, up to and including 1.2.11; from 2.0.0, up to and including 2.0.3

Published 2021-12-08. Last modified 2026-06-17.