CVE-2019-17656: Fortinet FortiOS

Medium severity, CVSS 6.5. EPSS: 1.6% chance of exploitation in the next 30 days.

A Stack-based Buffer Overflow vulnerability in the HTTPD daemon of FortiOS 6.0.10 and below, 6.2.2 and below and FortiProxy 1.0.x, 1.1.x, 1.2.9 and below, 2.0.0 and below may allow an authenticated remote attacker to crash the service by sending a malformed PUT request to the server. Fortinet is not aware of any successful exploitation of this vulnerability that would lead to code execution.

Affected products

• Fortinet FortiOS: up to and including 6.0.10; from 6.2.0, up to and including 6.2.2
• Fortinet FortiProxy: from 1.0.0, before 1.2.10 (fixed in 1.2.10); from 2.0.0, before 2.0.2 (fixed in 2.0.2)

Published 2021-04-12. Last modified 2026-06-17.