CVE-2025-59718

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.

CVSS v3.1 Score

9.8

CRITICAL

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

CISA Known Exploited Vulnerability

This vulnerability is actively exploited in the wild.

Added: Dec 16, 2025 Remediation due: Dec 23, 2025

Weakness Type (CWE)

CWE-347 CWE-347

Affected Products

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

References

Advisories & Patches

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

Other References

https://arcticwolf.com/resources/blog/arctic-wolf-observes-malicious-sso-logins-following-disclosure-cve-2025-59718-cve-2025-59719/ https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-59718

Frequently Asked Questions

What is CVE-2025-59718? +

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. It has a CVSS v3.1 base score of 9.8 (CRITICAL). This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog, indicating active exploitation in the wild.

How severe is CVE-2025-59718? +

CVE-2025-59718 has a CVSS v3.1 score of 9.8 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately.

What products are affected by CVE-2025-59718? +

CVE-2025-59718 affects products from fortinet, specifically: fortios, fortiproxy, fortiswitchmanager. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-59718? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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