Critical Vulnerabilities in Multiple Fortinet Products
12 December 2025
Fortinet has released security updates to address critical vulnerabilities affecting their FortiOS, FortiWeb, FortiProxy and FortiSwitchManager products. Users and administrators of affected product versions are advised to update to the latest version immediately.
Background
Fortinet has released security updates to address critical vulnerabilities (CVE-2025-59718 and CVE-2025-59719) affecting FortiOS, FortiProxy, FortiSwitchManager and FortiWeb. Both vulnerabilities have a Common Vulnerability Scoring System (CVSS v3.0) score of 9.8 out of 10.
Impact
Successful exploitation of the vulnerabilities could lead to the following:
CVE-2025-59718: This vulnerability involves improper verification of cryptographic signatures in versions of Fortinet FortiOS, FortiProxy, and FortiSwitchManager, which could allow an unauthenticated attacker to bypass FortiCloud SSO login authentication via a crafted SAML response message.
CVE-2025-59719: This vulnerability involves improper verification of cryptographic signatures in Fortinet FortiWeb, which could allow an unauthenticated attacker to bypass FortiCloud SSO login authentication via a crafted SAML response message.
Affected Products
The vulnerabilities affect the following product versions:
FortiOS
7.0.0 through 7.0.17
7.2.0 through 7.2.11
7.4.0 through 7.4.8
7.6.0 through 7.6.3
FortiProxy
7.0.0 through 7.0.21
7.2.0 through 7.2.14
7.4.0 through 7.4.10
7.6.0 through 7.6.3
FortiSwitchManager
7.0.0 through 7.0.5
7.2.0 through 7.2.6
FortiWeb
7.4.0 through 7.4.9
7.6.0 through 7.6.4
8.0.0
Mitigation
Users and administrators of affected products are advised to update the affected products to the latest version immediately.
Workaround
If patching is not immediately possible, administrators may consider turning off the FortiCloud login feature (if enabled) temporarily until upgrading to a non-affected version. To turn off FortiCloud login, go to System -> Settings -> Switch “Allow administrative login using FortiCloud SSO” to Off. Alternatively, type the following command in the CLI:
config system global
set admin-forticloud-sso-login disable
end
References
https://fortiguard.fortinet.com/psirt/FG-IR-25-647
https://nvd.nist.gov/vuln/detail/CVE-2025-59718
https://nvd.nist.gov/vuln/detail/CVE-2025-59719
https://arcticwolf.com/resources/blog/cve-2025-59718-and-cve-2025-59719/
