CVE-2025-59718: Fortinet Multiple Products Improper Verification of Cryptographic Signature Vulnerability

Critical severity, CVSS 9.8. Actively exploited: in CISA KEV since 2025-12-16. EPSS: 68.3% chance of exploitation in the next 30 days.

A improper verification of cryptographic signature vulnerability in Fortinet FortiOS 7.6.0 through 7.6.3, FortiOS 7.4.0 through 7.4.8, FortiOS 7.2.0 through 7.2.11, FortiOS 7.0.0 through 7.0.17, FortiProxy 7.6.0 through 7.6.3, FortiProxy 7.4.0 through 7.4.10, FortiProxy 7.2.0 through 7.2.14, FortiProxy 7.0.0 through 7.0.21, FortiSwitchManager 7.2.0 through 7.2.6, FortiSwitchManager 7.0.0 through 7.0.5 allows an unauthenticated attacker to bypass the FortiCloud SSO login authentication via a crafted SAML response message.

Affected products

• Fortinet FortiOS: from 7.0.0, before 7.0.18 (fixed in 7.0.18); from 7.2.0, before 7.2.12 (fixed in 7.2.12); from 7.4.0, before 7.4.9 (fixed in 7.4.9); from 7.6.0, before 7.6.4 (fixed in 7.6.4)
• Fortinet FortiProxy: from 7.0.0, before 7.0.22 (fixed in 7.0.22); from 7.2.0, before 7.2.15 (fixed in 7.2.15); from 7.4.0, before 7.4.11 (fixed in 7.4.11); from 7.6.0, before 7.6.4 (fixed in 7.6.4)
• Fortinet Fortiswitchmanager: from 7.0.0, before 7.0.6 (fixed in 7.0.6); from 7.2.0, before 7.2.7 (fixed in 7.2.7)
• Siemens Ruggedcom APE1808 Firmware: affected versions not specified

Published 2025-12-09. Last modified 2026-06-17.