CVE-2026-59840: Fortinet FortiOS

Medium severity, CVSS 4.3. EPSS: 0.3% chance of exploitation in the next 30 days.

A buffer over-read vulnerability in Fortinet FortiOS 7.6.0 through 7.6.3, FortiOS 7.4.0 through 7.4.8, FortiOS 7.2 all versions, FortiOS 7.0 all versions, FortiOS 6.4 all versions, FortiProxy 7.6.0 through 7.6.5, FortiProxy 7.4.0 through 7.4.13, FortiProxy 7.2 all versions, FortiProxy 7.0 all versions may allow attacker to information disclosure via <insert attack vector here>

Affected products

• Fortinet FortiOS: from 7.2.0, before 7.4.9 (fixed in 7.4.9); from 7.6.0, up to and including 7.6.2
• Fortinet FortiProxy: from 7.2.0, before 7.4.14 (fixed in 7.4.14); from 7.6.0, before 7.6.6 (fixed in 7.6.6)

Published 2026-07-14. Last modified 2026-08-11.