Critical FortiGate SSO Vulnerability Actively Exploited in the Wild

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Exploitation of FortiGate SSO Vulnerabilities by Threat Actors Threat actors are actively exploiting critical authentication bypass vulnerabilities in Fortinet's FortiGate appliances, specifically CVE-2025-59718 and CVE-2025-59719. These vulnerabilities allow unauthenticated single sign-on (SSO) logins via malicious SAML messages, granting administrative access to attackers. Fortinet disclosed these flaws in a PSIRT advisory on December 9, 2025. 4 sources 88