CVE-2025-59718

9.8 CRITICAL CISA KEV - Actively Exploited

Published: December 09, 2025 Modified: June 09, 2026

Description

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.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0

Vector String

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory

https://fortiguard.fortinet.com/psirt/FG-IR-25-647

Source: psirt@fortinet.com

Vendor Advisory

https://arcticwolf.com/resources/blog/arctic-wolf-observes-malicious-sso-logins-following-disclosure-cve-2025-59718-cve-2025-59719/

Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0

Third Party Advisory

https://cert-portal.siemens.com/productcert/html/ssa-864900.html

Source: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e

Third Party Advisory

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-59718

Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0

US Government Resource

4 reference(s) from NVD

Quick Stats

CVSS v3 Score

9.8 / 10.0

EPSS (Exploit Probability)

9.5%

93th percentile

Exploitation Status

Actively Exploited

Remediation due: 2025-12-23

Weaknesses (CWE)

CWE-347

Affected Vendors

fortinet siemens

Related CVEs

CVE-2026-46546 N/A

CVE-2026-44634 N/A

CVE-2026-53675 4.3

CVE-2026-53674 7.1

CVE-2026-53673 8.1