CVE-2021-26095: Fortinet FortiMail

High severity, CVSS 8.8. EPSS: 0.7% chance of exploitation in the next 30 days.

The combination of various cryptographic issues in the session management of FortiMail 6.4.0 through 6.4.4 and 6.2.0 through 6.2.6, including the encryption construction of the session cookie, may allow a remote attacker already in possession of a cookie to possibly reveal and alter or forge its content, thereby escalating privileges.

Affected products

• Fortinet FortiMail: from 6.2.0, up to and including 6.2.6; from 6.4.0, before 6.4.5 (fixed in 6.4.5)

Published 2021-07-20. Last modified 2026-06-17.