CVE-2025-59718

CRITICAL KEV

Fortinet FortiOS/FortiProxy/FortiSwitchManager SAML Signature Verification Bypass

Title source: llm
STIX 2.1

Exploitation Summary

CVE-2025-59718 is actively exploited and listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added December 16, 2025. EIP tracks 3 public exploits from researchers including exfil0, adminlove520, moften.

AI-analyzed exploit summary This repository contains a functional proof-of-concept exploit for CVE-2025-59718, an authentication bypass vulnerability in Fortinet products due to improper SAML signature verification. The exploit crafts unsigned SAML responses to gain administrative access and includes features for bulk scanning, proxy support, and post-authentication actions.

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.

Exploits (3)

nomisec WORKING POC 4 stars
by exfil0 · poc
https://github.com/exfil0/CVE-2025-59718-PoC

This repository contains a functional proof-of-concept exploit for CVE-2025-59718, an authentication bypass vulnerability in Fortinet products due to improper SAML signature verification. The exploit crafts unsigned SAML responses to gain administrative access and includes features for bulk scanning, proxy support, and post-authentication actions.

Classification
Working Poc 95%
Attack Type
Auth Bypass
Complexity
Moderate
Reliability
Reliable
Target: Fortinet FortiOS, FortiProxy, FortiSwitchManager (versions prior to 7.4.9)
No auth needed
Prerequisites: Network access to target · FortiCloud SSO enabled on target
devstral-2 · analyzed Feb 16, 2026 Full analysis →
github WORKING POC 2 stars
by adminlove520 · pythonpoc
https://github.com/adminlove520/CVE-Poc_All_in_One/tree/main/2025/CVE-2025-59718

This repository contains a functional Python exploit for CVE-2025-59718, an authentication bypass vulnerability in Fortinet products (FortiOS, FortiProxy, FortiSwitchManager) due to improper SAML signature verification. The exploit crafts unsigned SAML responses to gain administrative access and supports features like multi-threading, proxy usage, and post-authentication actions.

Classification
Working Poc 95%
Attack Type
Auth Bypass
Complexity
Moderate
Reliability
Reliable
Target: Fortinet FortiOS, FortiProxy, FortiSwitchManager (versions prior to 7.4.9)
No auth needed
Prerequisites: FortiCloud SSO enabled on target · network access to target · Python 3.8+ with requests library
devstral-2 · analyzed Feb 27, 2026 Full analysis →
nomisec SCANNER 2 stars
by moften · poc
https://github.com/moften/CVE-2025-59718-Fortinet-Poc

This repository contains a Python-based scanner for detecting vulnerabilities CVE-2025-59718 and CVE-2025-59719 in Fortinet devices (FortiOS, FortiProxy, FortiSwitchManager, FortiWeb). It supports passive fingerprinting, active non-destructive tests, and authenticated SSH checks.

Classification
Scanner 95%
Attack Type
Info Leak
Complexity
Moderate
Reliability
Reliable
Target: Fortinet FortiOS, FortiProxy, FortiSwitchManager, FortiWeb
No auth needed
Prerequisites: Network access to target device · Optional SSH credentials for authenticated checks
devstral-2 · analyzed Feb 16, 2026 Full analysis →

Scores

CVSS v3 9.8
EPSS 0.1207
EPSS Percentile 94.0%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation active
Automatable yes
Technical Impact total

Details

CISA KEV 2025-12-16
VulnCheck KEV 2025-12-15
ENISA EUVD EUVD-2025-202198
CWE
CWE-347
Status published
Products (14)
Fortinet/FortiOS 7.0.0 - 7.0.17
fortinet/fortios 7.0.0 - 7.0.18
Fortinet/FortiOS 7.2.0 - 7.2.11
Fortinet/FortiOS 7.4.0 - 7.4.8
Fortinet/FortiOS 7.6.0 - 7.6.3
Fortinet/FortiProxy 7.0.0 - 7.0.21
fortinet/fortiproxy 7.0.0 - 7.0.22
Fortinet/FortiProxy 7.2.0 - 7.2.14
Fortinet/FortiProxy 7.4.0 - 7.4.10
Fortinet/FortiProxy 7.6.0 - 7.6.3
... and 4 more
Published Dec 09, 2025
KEV Added Dec 16, 2025
Tracked Since Feb 18, 2026