ClosedCriticalPatched

Fortinet Multiple Products: Multiple Products Improper Verification of Cryptographic Signature Vulnerability

Fortinet Multiple Products

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. Added to CISA KEV on 2025-12-16.

Why this severity: CVSS 9.1 (CNA, v3.1); actively exploited (CISA KEV)

Started: Dec 16, 2025
Closed: Dec 16, 2025
CVE: CVE-2025-59718

Follow this incident

Updated Dec 16, 2025

Affected

See vendor advisory / CISA notes (versions not always listed in KEV feed)

Fixed in

See vendor advisory linked in sources

Timeline1

Dec 16, 2025
CISA added CVE-2025-59718 to the KEV catalog (due 2025-12-23).

Advisories4

Notes & caveats

Derived from CISA KEV JSON feed catalogVersion 2026.10.21. CVSS from the CVE record (cvelistV5). Exact affected/fixed version strings are not always in the KEV record; verify against the vendor advisory URL. startedAt uses dateAdded (exploitation may have begun earlier; many entries are older CVEs newly confirmed as exploited in 2025).

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