CVE-2025-59719

critical

Description

An improper verification of cryptographic signature vulnerability in Fortinet FortiWeb 8.0.0, FortiWeb 7.6.0 through 7.6.4, FortiWeb 7.4.0 through 7.4.9 may allow an unauthenticated attacker to bypass the FortiCloud SSO login authentication via a crafted SAML response message.

https://www.theregister.com/2026/01/28/fortinet_forticloud_vuln/

https://www.databreachtoday.com/fortinet-locks-down-forticloud-sso-amid-zero-day-attacks-a-30612

https://www.cisa.gov/news-events/alerts/2026/01/28/fortinet-releases-guidance-address-ongoing-exploitation-authentication-bypass-vulnerability-cve-2026

https://securityaffairs.com/187426/security/fortinet-patches-actively-exploited-fortios-sso-auth-bypass-cve-2026-24858.html

https://www.securityweek.com/fortinet-confirms-forticloud-sso-exploitation-against-patched-devices/

https://securityaffairs.com/187250/security/fortinet-warns-of-active-forticloud-sso-bypass-affecting-updated-devices.html

https://www.securityweek.com/new-wave-of-attacks-targeting-fortigate-firewalls/

https://www.fortinet.com/blog/psirt-blogs/analysis-of-sso-abuse-on-fortios

https://www.darkreading.com/cloud-security/fortinet-firewalls-malicious-configuration-changes

https://thehackernews.com/2026/01/automated-fortigate-attacks-exploit.html

https://securityaffairs.com/187194/hacking/arctic-wolf-detects-surge-in-automated-fortinet-fortigate-firewall-configuration-attacks.html

https://www.helpnetsecurity.com/2026/01/21/patched-fortigate-compromised-via-cve-2025-59718/

https://securityaffairs.com/185896/hacking/u-s-cisa-adds-a-flaw-in-watchguard-fireware-os-to-its-known-exploited-vulnerabilities-catalog.html

https://www.bleepingcomputer.com/news/security/over-25-000-forticloud-sso-devices-exposed-to-remote-attacks/

https://thehackernews.com/2025/12/watchguard-warns-of-active-exploitation.html

https://securityaffairs.com/185765/security/u-s-cisa-adds-a-flaw-in-multiple-fortinet-products-to-its-known-exploited-vulnerabilities-catalog.html

https://www.securityweek.com/in-the-wild-exploitation-of-fresh-fortinet-flaws-begins/

https://www.bleepingcomputer.com/news/security/hackers-exploit-newly-patched-fortinet-auth-bypass-flaws/

https://thehackernews.com/2025/12/fortinet-fortigate-under-active-attack.html

https://securityaffairs.com/185748/security/hackers-are-exploiting-critical-fortinet-flaws-days-after-patch-release.html

https://www.securityweek.com/fortinet-patches-exploited-forticloud-sso-authentication-bypass/

https://thehackernews.com/2026/01/fortinet-confirms-active-forticloud-sso.html

https://www.theregister.com/2026/01/22/fortigate_firewalls_hit_by_silent/

https://www.bleepingcomputer.com/news/security/hackers-breach-fortinet-fortigate-devices-steal-firewall-configs/

https://www.helpnetsecurity.com/2025/12/17/fortigate-vulnerability-cve-2025-59718-exploited/

https://www.securityweek.com/fortinet-patches-critical-authentication-bypass-vulnerabilities/

https://thehackernews.com/2025/12/fortinet-ivanti-and-sap-issue-urgent.html

https://securityaffairs.com/185546/security/fortinet-fixed-two-critical-authentication-bypass-vulnerabilities.html

https://www.theregister.com/2025/12/09/december_2025_patch_tuesday/

https://www.bleepingcomputer.com/news/security/fortinet-warns-of-critical-forticloud-sso-login-auth-bypass-flaws/

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

Details

Source: Mitre, NVD

Published: 2025-12-09

Updated: 2025-12-09

Risk Information

CVSS v2

Base Score: 10

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

Severity: Critical

CVSS v3

Base Score: 9.8

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

Severity: Critical

EPSS

EPSS: 0.00096

Vulnerability Watch

Tenable Research has classified this CVE under the following Vulnerability Watch classification, which includes active and historical (inactive) classifications. You can learn more about these classifications on our blog.

Vulnerability of Interest

Detections

Analytics