CVE-2021-26091: Fortinet FortiMail

High severity, CVSS 7.5. EPSS: 0.3% chance of exploitation in the next 30 days.

A use of a cryptographically weak pseudo-random number generator vulnerability in the authenticator of the Identity Based Encryption service of FortiMail 6.4.0 through 6.4.4, and 6.2.0 through 6.2.7 may allow an unauthenticated attacker to infer parts of users authentication tokens and reset their credentials.

Affected products

• Fortinet FortiMail: from 6.2.0, before 6.4.5 (fixed in 6.4.5)

Published 2025-03-24. Last modified 2026-06-17.