Fortinet Multiple Products Improper Verification of Cryptographic Signature
What to do
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
CISA deadline 2025-12-23 · passed 8 months ago · applies to US federal civilian agencies; used elsewhere as a reference SLA
What happened
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.
Who is affected
Fortinet Multiple Products. Affected version ranges are listed in the vendor advisory and the NVD entry linked under Sources.
Weakness class: CWE-347.
Timeline
- Added to CISA KEVExploitation in the wild confirmed by CISA
- CISA remediation deadlinepassed 8 months ago
Sources
- NVD entry for CVE-2025-59718 nvd.nist.gov/vuln/detail/CVE-2025-59718
- CISA Known Exploited Vulnerabilities catalog www.cisa.gov/known-exploited-vulnerabilities-catalog
- fortiguard.fortinet.com fortiguard.fortinet.com/psirt/FG-IR-25-647
- docs.fortinet.com docs.fortinet.com/upgrade-tool/fortigate
- nvd.nist.gov nvd.nist.gov/vuln/detail/CVE-2025-59718