CVE-2018-9194: Fortinet FortiOS

Medium severity, CVSS 5.9. EPSS: 1.1% chance of exploitation in the next 30 days.

A plaintext recovery of encrypted messages or a Man-in-the-middle (MiTM) attack on RSA PKCS #1 v1.5 encryption may be possible without knowledge of the server's private key. Fortinet FortiOS 5.4.6 to 5.4.9, 6.0.0 and 6.0.1 are vulnerable by such attack under VIP SSL feature when CPx being used.

Affected products

• Fortinet FortiOS: from 5.4.6, up to and including 5.4.9; version 6.0.0 only; version 6.0.1 only

Published 2018-09-05. Last modified 2026-06-17.