CVE-2025-59718

Name: CVE-2025-59718
Creator: NVD / NIST
Published: 2025-12-09T18:15:54.983+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10Actively ExploitedEPSS 65.83%

Last modified Jun 17, 2026

CVE-2025-59718 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. 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.. CISA has confirmed active exploitation in the wild. EPSS estimates a 65.83% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

9.8/10

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

EPSS Probability

65.83%

99.2th percentile

Probability of exploitation in the next 30 days. Learn more

Exploitation Status

This vulnerability is listed in CISA’s Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. Federal agencies must remediate by Dec 23, 2025.

Weakness Enumeration

CWE-347

Affected Software

Vendor	Product	Versions
Fortinet	Fortiproxy	>= 7.0.0, < 7.0.22
Fortinet	Fortiproxy	>= 7.2.0, < 7.2.15
Fortinet	Fortiproxy	>= 7.4.0, < 7.4.11
Fortinet	Fortiproxy	>= 7.6.0, < 7.6.4
Fortinet	Fortiswitchmanager	>= 7.0.0, < 7.0.6
Fortinet	Fortiswitchmanager	>= 7.2.0, < 7.2.7
Fortinet	Fortios	>= 7.0.0, < 7.0.18
Fortinet	Fortios	>= 7.2.0, < 7.2.12
Fortinet	Fortios	>= 7.4.0, < 7.4.9
Fortinet	Fortios	>= 7.6.0, < 7.6.4
Siemens	Ruggedcom Ape1808 Firmware	All versions

References

https://fortiguard.fortinet.com/psirt/FG-IR-25-647Vendor Advisory
https://arcticwolf.com/resources/blog/arctic-wolf-observes-malicious-sso-logins-following-disclosure-cve-2025-59718-cve-2025-59719/Third Party Advisory
https://cert-portal.siemens.com/productcert/html/ssa-864900.htmlThird Party Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-59718US Government Resource

Timeline

Published: Dec 9, 2025
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2025-59718?

How severe is CVE-2025-59718?

CVE-2025-59718 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 65.83% probability of exploitation in the next 30 days. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog.

How do I fix CVE-2025-59718?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2025-59718?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST