CVE Watch—

CVE-2025-59718

Fortinet Multiple Products Improper Verification of Cryptographic Signature Vulnerability

CVSS

—

No CVSS

EPSS

68.3%

p99

KEV

YES

Dec 16, 2025

Exploit Today

0-100

Published: — · Last modified: —

EPSS · 30d

68.3%EPSS · 30 days68.3%

2026-09-172026-10-15

KEV catalog record

Product

Fortinet / Multiple Products

Vulnerability

Fortinet Multiple Products Improper Verification of Cryptographic Signature Vulnerability

Added to KEV

Dec 16, 2025

Remediate by

Dec 23, 2025

Known ransomware use

Summary 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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