CVE-2025-25253: Fortinet FortiOS

High severity, CVSS 7.5. EPSS: 0.1% chance of exploitation in the next 30 days.

An Improper Validation of Certificate with Host Mismatch vulnerability [CWE-297] in FortiProxy version 7.6.1 and below, version 7.4.8 and below, 7.2 all versions, 7.0 all versions and FortiOS version 7.6.2 and below, version 7.4.8 and below, 7.2 all versions, 7.0 all versions ZTNA proxy may allow an unauthenticated attacker in a man-in-the middle position to intercept and tamper with connections to the ZTNA proxy

Affected products

• Fortinet FortiOS: from 7.0.0, before 7.4.9 (fixed in 7.4.9); from 7.6.0, before 7.6.3 (fixed in 7.6.3)
• Fortinet FortiProxy: from 7.0.0, before 7.4.9 (fixed in 7.4.9); from 7.6.0, before 7.6.2 (fixed in 7.6.2)

Published 2025-10-14. Last modified 2026-06-17.