Known Exploited Vulnerability
9.8
CRITICAL CVSS 3.1
CVE-2025-59718
Fortinet Multiple Products Improper Verification of Cryptographic Signature Vulnerability - [Actively Exploited]
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.

INFO

Published Date :

Dec. 9, 2025, 6:15 p.m.

Last Modified :

Dec. 17, 2025, 1:54 p.m.

Remotely Exploit :

Yes !
CISA Notification
CISA KEV (Known Exploited Vulnerabilities)

For the benefit of the cybersecurity community and network defenders—and to help every organization better manage vulnerabilities and keep pace with threat activity—CISA maintains the authoritative source of vulnerabilities that have been exploited in the wild.

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.

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

Affected Products

The following products are affected by CVE-2025-59718 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Fortinet fortios
2 Fortinet fortiswitchmanager
3 Fortinet fortiproxy
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 CRITICAL 6abe59d8-c742-4dff-8ce8-9b0ca1073da8
CVSS 3.1 CRITICAL [email protected]
Solution
Update FortiOS and FortiProxy to a fixed version to address SAML bypass.
  • Update FortiOS to a fixed version.
  • Update FortiProxy to a fixed version.
  • Update FortiSwitchManager to a fixed version.
Public PoC/Exploit Available at Github

CVE-2025-59718 has a 6 public PoC/Exploit available at Github. Go to the Public Exploits tab to see the list.

References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2025-59718.

URL Resource
https://fortiguard.fortinet.com/psirt/FG-IR-25-647 Vendor Advisory
https://arcticwolf.com/resources/blog/arctic-wolf-observes-malicious-sso-logins-following-disclosure-cve-2025-59718-cve-2025-59719/ Third Party Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-59718 US Government Resource
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2025-59718 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2025-59718 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

PoC para determinar si Fortinet es vulnerable a CVE-2025-59718 / CVE-2025-59719

Python

Updated: 3 weeks, 3 days ago
1 stars 0 fork 0 watcher
Born at : Dec. 27, 2025, 4:24 a.m. This repo has been linked 2 different CVEs too.

Fortinet announced two closely related authentication‑bypass vulnerabilities on 9 December 2025. Both flaws involve improper verification of cryptographic signatures (CWE‑347) in the handling of SAML responses for the FortiCloud SSO login feature.

Python

Updated: 1 month ago
1 stars 3 fork 3 watcher
Born at : Dec. 17, 2025, 11:33 a.m. This repo has been linked 2 different CVEs too.

Mise en place d'un système de veille et d'analyse de menaces pour une entreprise du secteur de l'énergie

Updated: 1 month, 1 week ago
0 stars 0 fork 0 watcher
Born at : Dec. 15, 2025, 2:42 p.m. This repo has been linked 2 different CVEs too.

parse SAML responses from a pcap

Python

Updated: 1 month, 1 week ago
0 stars 0 fork 0 watcher
Born at : Dec. 11, 2025, 2:45 p.m. This repo has been linked 2 different CVEs too.

CVE-2025-59718

Python

Updated: 1 month, 1 week ago
6 stars 4 fork 4 watcher
Born at : Dec. 11, 2025, 9:55 a.m. This repo has been linked 1 different CVEs too.

None

Python

Updated: 2 weeks ago
1 stars 0 fork 0 watcher
Born at : Oct. 29, 2024, 8:10 p.m. This repo has been linked 11 different CVEs too.

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2025-59718 vulnerability anywhere in the article.

  • The Cyber Express
CISA Adds Five Enterprise Software Flaws to Known Exploited Vulnerabilities Catalog

The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has added five enterprise software flaws to its Known Exploited Vulnerabilities (KEV) Catalog in an 18-hour span. On January 22, CISA a ... Read more

Published Date: Jan 23, 2026 (10 hours, 17 minutes ago)
  • The Hacker News
Fortinet Confirms Active FortiCloud SSO Bypass on Fully Patched FortiGate Firewalls

Fortinet has officially confirmed that it's working to completely plug a FortiCloud SSO authentication bypass vulnerability following reports of fresh exploitation activity on fully-patched firewalls. ... Read more

Published Date: Jan 23, 2026 (20 hours, 9 minutes ago)
  • CybersecurityNews
Fortinet Confirms Active Exploitation of FortiCloud SSO Authentication Bypass Vulnerability

Fortinet confirms active exploitation of a FortiCloud SSO authentication bypass vulnerability, with a new automated campaign targeting even fully patched FortiGate devices. Cybersecurity firm Arctic W ... Read more

Published Date: Jan 23, 2026 (20 hours, 46 minutes ago)
  • The Cyber Express
The Cyber Express Weekly Roundup: FortiOS Exploits, Ransomware, Hacktivist Surge, and EU Telecom Rules

The third week of 2026 highlights a series of cybersecurity events affecting businesses, critical infrastructure, and regulatory compliance. This week, network administrators are grappling with the ex ... Read more

Published Date: Jan 23, 2026 (21 hours, 20 minutes ago)
  • BleepingComputer
Fortinet confirms critical FortiCloud auth bypass not fully patched

Days after admins began reporting that their fully patched firewalls are being hacked, Fortinet confirmed it's working to fully address a critical FortiCloud SSO authentication bypass vulnerability th ... Read more

Published Date: Jan 23, 2026 (22 hours ago)
  • The Cyber Express
GitLab Releases Critical Patch Updates to Address Multiple High-Severity Vulnerabilities

GitLab has issued a new GitLab patch release addressing a range of security vulnerabilities and stability issues across multiple supported versions. The latest updates, versions 18.8.2, 18.7.2, and 18 ... Read more

Published Date: Jan 23, 2026 (1 day ago)
  • Daily CyberSecurity
“New” Path of Attack: Fully Upgraded Fortinet Devices Hit by SSO Exploits

Fortinet is investigating a concerning new wave of attacks targeting its network security devices, where threat actors are successfully compromising systems that have already been fully patched agains ... Read more

Published Date: Jan 23, 2026 (1 day, 4 hours ago)
  • The Register
FortiGate firewalls hit by silent SSO intrusions and config theft

FortiGate firewalls are getting quietly reconfigured and stripped down by miscreants who've figured out how to sidestep SSO protections and grab sensitive settings right out of the box. That's accordi ... Read more

Published Date: Jan 22, 2026 (1 day, 16 hours ago)
  • CybersecurityNews
FortiGate Firewalls Hacked in Automated Attacks to Steal Configuration Data

A new cluster of automated malicious activity targeting FortiGate firewall devices. Beginning January 15, 2026, threat actors have been observed executing unauthorized configuration changes, establish ... Read more

Published Date: Jan 22, 2026 (1 day, 19 hours ago)
  • The Cyber Express
Fortinet Admins Report Active Exploits on “Fixed” FortiOS 7.4.9 Firmware

Network administrators worldwide are scrambling this morning following credible reports that the critical Fortinet Single Sign-On (SSO) vulnerability, tracked as CVE-2025-59718, is being actively expl ... Read more

Published Date: Jan 22, 2026 (1 day, 20 hours ago)
  • BleepingComputer
Hackers breach Fortinet FortiGate devices, steal firewall configs

Fortinet FortiGate devices are being targeted in automated attacks that create rogue accounts and steal firewall configuration data, according to cybersecurity company Arctic Wolf. The campaign starte ... Read more

Published Date: Jan 22, 2026 (1 day, 20 hours ago)
  • security.nl
Beheerders melden aanvallen op volledig gepatchte Fortinet FortiGate-firewalls

Volledig gepatchte Fortinet FortiGate-firewalls zijn het doelwit van aanvallen en Fortinet zou inmiddels tegenover klanten hebben bevestigd dat er een update voor het onderliggende probleem wordt ontw ... Read more

Published Date: Jan 22, 2026 (1 day, 22 hours ago)
  • The Hacker News
Automated FortiGate Attacks Exploit FortiCloud SSO to Alter Firewall Configurations

Cybersecurity company Arctic Wolf has warned of a "new cluster of automated malicious activity" that involves unauthorized firewall configuration changes on Fortinet FortiGate devices. The activity, i ... Read more

Published Date: Jan 22, 2026 (2 days, 2 hours ago)
  • CybersecurityNews
Fortinet SSO Vulnerability Actively Exploited to Hack Firewalls and Gain Admin Access

A critical vulnerability in Fortinet’s Single Sign-On (SSO) feature for FortiGate firewalls, tracked as CVE-2025-59718, is under active exploitation. Attackers are leveraging it to create unauthorized ... Read more

Published Date: Jan 22, 2026 (2 days, 5 hours ago)
  • Daily CyberSecurity
New Campaign Targets FortiGate Firewalls with Unauthorized Config Changes

A fresh wave of automated cyberattacks is targeting FortiGate firewalls, exploiting unauthorized access to create backdoors and steal sensitive configuration data. Security researchers at Arctic Wolf ... Read more

Published Date: Jan 22, 2026 (2 days, 6 hours ago)
  • Help Net Security
Fully patched FortiGate firewalls are getting compromised via CVE-2025-59718?

CVE-2025-59718, a critical authentication bypass flaw that attackers exploited in December 2025 to compromise FortiGate appliances, appears to persist in newer, purportedly fixed releases of the under ... Read more

Published Date: Jan 21, 2026 (2 days, 13 hours ago)
  • BleepingComputer
Fortinet admins report patched FortiGate firewalls getting hacked

Fortinet customers are seeing attackers exploiting a patch bypass for a previously fixed critical FortiGate authentication vulnerability (CVE-2025-59718) to hack patched firewalls. One of the affected ... Read more

Published Date: Jan 21, 2026 (2 days, 14 hours ago)
  • europa.eu
Cyber Brief 26-01 - December 2025

Cyber Brief (December 2025)January 5, 2025 - Version: 1TLP:CLEARExecutive summaryWe analysed 368 open source reports for this Cyber Security Brief[^1].Relating to cyber policy and law enforcement, the ... Read more

Published Date: Jan 05, 2026 (2 weeks, 4 days ago)
  • BleepingComputer
Over 10K Fortinet firewalls exposed to actively exploited 2FA bypass

Over 10,000 Fortinet firewalls are still exposed online and vulnerable to ongoing attacks exploiting a five-year-old critical two-factor authentication (2FA) bypass vulnerability. Fortinet released Fo ... Read more

Published Date: Jan 02, 2026 (3 weeks ago)
  • CybersecurityNews
Cybersecurity Weekly Recap – PornHub Breach, Cisco 0-Day, Amazon Detains DPRK IT Worker, and more

In a week that revealed the flaws in digital trust, cybersecurity headlines were filled with high-profile breaches, zero-day exploits, and bold nation-state espionage. Attackers claimed to have swiped ... Read more

Published Date: Dec 21, 2025 (1 month ago)

The following table lists the changes that have been made to the CVE-2025-59718 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • Modified Analysis by [email protected]

    Dec. 17, 2025

    Action Type Old Value New Value
    Changed CPE Configuration OR *cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:* versions from (including) 7.0.0 up to (including) 7.0.17 *cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:* versions from (including) 7.2.0 up to (including) 7.2.11 *cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:* versions from (including) 7.4.0 up to (including) 7.4.8 *cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:* versions from (including) 7.6.0 up to (including) 7.6.3 *cpe:2.3:a:fortinet:fortiproxy:*:*:*:*:*:*:*:* versions from (including) 7.0.0 up to (including) 7.0.21 *cpe:2.3:a:fortinet:fortiproxy:*:*:*:*:*:*:*:* versions from (including) 7.2.0 up to (including) 7.2.14 *cpe:2.3:a:fortinet:fortiproxy:*:*:*:*:*:*:*:* versions from (including) 7.4.0 up to (including) 7.4.10 *cpe:2.3:a:fortinet:fortiproxy:*:*:*:*:*:*:*:* versions from (including) 7.6.0 up to (including) 7.6.3 *cpe:2.3:a:fortinet:fortiswitchmanager:*:*:*:*:*:*:*:* versions from (including) 7.0.0 up to (including) 7.0.5 *cpe:2.3:a:fortinet:fortiswitchmanager:*:*:*:*:*:*:*:* versions from (including) 7.2.0 up to (including) 7.2.6 OR *cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:* versions from (including) 7.6.0 up to (excluding) 7.6.4 *cpe:2.3:a:fortinet:fortiproxy:*:*:*:*:*:*:*:* versions from (including) 7.0.0 up to (excluding) 7.0.22 *cpe:2.3:a:fortinet:fortiproxy:*:*:*:*:*:*:*:* versions from (including) 7.2.0 up to (excluding) 7.2.15 *cpe:2.3:a:fortinet:fortiproxy:*:*:*:*:*:*:*:* versions from (including) 7.4.0 up to (excluding) 7.4.11 *cpe:2.3:a:fortinet:fortiproxy:*:*:*:*:*:*:*:* versions from (including) 7.6.0 up to (excluding) 7.6.4 *cpe:2.3:a:fortinet:fortiswitchmanager:*:*:*:*:*:*:*:* versions from (including) 7.0.0 up to (excluding) 7.0.6 *cpe:2.3:a:fortinet:fortiswitchmanager:*:*:*:*:*:*:*:* versions from (including) 7.2.0 up to (excluding) 7.2.7 *cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:* versions from (including) 7.0.0 up to (excluding) 7.0.18 *cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:* versions from (including) 7.2.0 up to (excluding) 7.2.12 *cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:* versions from (including) 7.4.0 up to (excluding) 7.4.9
    Added Reference Type CISA-ADP: https://arcticwolf.com/resources/blog/arctic-wolf-observes-malicious-sso-logins-following-disclosure-cve-2025-59718-cve-2025-59719/ Types: Third Party Advisory
    Added Reference Type CISA-ADP: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-59718 Types: US Government Resource
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Dec. 16, 2025

    Action Type Old Value New Value
    Added Reference https://arcticwolf.com/resources/blog/arctic-wolf-observes-malicious-sso-logins-following-disclosure-cve-2025-59718-cve-2025-59719/
    Added Reference https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-59718
  • Initial Analysis by [email protected]

    Dec. 09, 2025

    Action Type Old Value New Value
    Added CPE Configuration OR *cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:* versions from (including) 7.0.0 up to (including) 7.0.17 *cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:* versions from (including) 7.2.0 up to (including) 7.2.11 *cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:* versions from (including) 7.4.0 up to (including) 7.4.8 *cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:* versions from (including) 7.6.0 up to (including) 7.6.3 *cpe:2.3:a:fortinet:fortiproxy:*:*:*:*:*:*:*:* versions from (including) 7.0.0 up to (including) 7.0.21 *cpe:2.3:a:fortinet:fortiproxy:*:*:*:*:*:*:*:* versions from (including) 7.2.0 up to (including) 7.2.14 *cpe:2.3:a:fortinet:fortiproxy:*:*:*:*:*:*:*:* versions from (including) 7.4.0 up to (including) 7.4.10 *cpe:2.3:a:fortinet:fortiproxy:*:*:*:*:*:*:*:* versions from (including) 7.6.0 up to (including) 7.6.3 *cpe:2.3:a:fortinet:fortiswitchmanager:*:*:*:*:*:*:*:* versions from (including) 7.0.0 up to (including) 7.0.5 *cpe:2.3:a:fortinet:fortiswitchmanager:*:*:*:*:*:*:*:* versions from (including) 7.2.0 up to (including) 7.2.6
    Added Reference Type Fortinet, Inc.: https://fortiguard.fortinet.com/psirt/FG-IR-25-647 Types: Vendor Advisory
  • New CVE Received by [email protected]

    Dec. 09, 2025

    Action Type Old Value New Value
    Added 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.
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    Added CWE CWE-347
    Added Reference https://fortiguard.fortinet.com/psirt/FG-IR-25-647
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
Vulnerability Scoring Details
Base CVSS Score: 9.8
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact