CVE-2025-59718

Fortinet Multiple Products Improper Verification of Cryptographic Signature Vulnerability

Fortinet — Multiple Products

Added to KEV catalog: 16 December 2025
Federal remediation due date: 23 December 2025
Weakness classification (CWE): CWE-347

CISA Description

Fortinet FortiOS, FortiSwitchMaster, FortiProxy, and FortiWeb contain an improper verification of cryptographic signature vulnerability that may allow an unauthenticated attacker to bypass the FortiCloud SSO login authentication via a crafted SAML message. Please be aware that CVE-2025-59719 pertains to the same problem and is mentioned in the same vendor advisory. Ensure to apply all patches mentioned in the advisory.

Required action

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Notes

https://fortiguard.fortinet.com/psirt/FG-IR-25-647 ; https://docs.fortinet.com/upgrade-tool/fortigate ; https://nvd.nist.gov/vuln/detail/CVE-2025-59718

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