Fortinet · Multiple Products

CVE-2025-59718

Fortinet Multiple Products Improper Verification of Cryptographic Signature Vulnerability

Evidence

Source & freshness

Full source status →

CISA KEV catalog Core KEV record

CVE, vendor/product, CISA dates, ransomware status, description, required action, and notes.

Catalog 2026.07.24 · Retrieved 2026-07-25 20:49 UTC Open official CISA feed ↗

MITRE CWE catalog CWE context

CWE names and plain-language weakness descriptions. CISA supplies the CWE assignment itself.

Retrieved 2026-07-25 20:59 UTC Open official MITRE CWE catalog ↗

National Vulnerability Database NVD technical context

CVSS metrics, NVD timeline, and related NVD record data are stored locally.

Retrieved Jul 25, 2026, 08:49 PM UTC Open NVD record ↗

CISA KEV record

CISA date added: 2025-12-16
CISA due date: 2025-12-23
Known ransomware use: Unknown

NVD risk context

9.8 CRITICAL

CVSS is a technical severity score. CISA’s KEV status remains the evidence that this vulnerability is known to be exploited.

View NVD record ↗

Attack vector

Network

The vulnerable service can be reached remotely over a network.

Attack complexity

Low

Exploitation does not require unusual conditions beyond normal attacker control.

Privileges required

None

The attacker does not need an existing account or privileges.

User interaction

None

No action by another user is required.

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.

NVD reference index

Vendor and remediation references

NVD has tagged these sources as vendor advisories, patches, mitigations, or release notes.

https://fortiguard.fortinet.com/psirt/FG-IR-25-647 ↗
Vendor Advisory NVD reference source: psirt@fortinet.com · Also linked in CISA notes

Other NVD references (3)

https://arcticwolf.com/resources/blog/arctic-wolf-observes-malicious-sso-logins-following-disclosure-cve-2025-59718-cve-2025-59719/ ↗
Third Party Advisory NVD reference source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
https://cert-portal.siemens.com/productcert/html/ssa-864900.html ↗
Third Party Advisory NVD reference source: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-59718 ↗
US Government Resource NVD reference source: 134c704f-9b21-4f2e-91b3-4a467353bcc0

MITRE CWE context

CWE classification

CWE-347 Improper Verification of Cryptographic Signature

The product does not verify, or incorrectly verifies, the cryptographic signature for data.

View official MITRE CWE details ↗

NVD record timing

NVD record timeline

These dates describe NVD’s record, not CISA’s KEV addition or remediation due date.

NVD published: Dec 09, 2025, 06:15 PM UTC
NVD last updated: Jun 17, 2026, 09:46 AM UTC

Advanced: view the technical CVSS vector

This standardized code is intended for security tools and technical analysts. The plain-language risk summary above explains its main points.

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

View NVD record ↗

CISA 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