Fortinet FortiOS and FortiProxy
YES - ON THE CISA KEV LIST
CVE-2024-55591
Fortinet FortiOS and FortiProxy Authentication Bypass Vulnerability
overdue since 2025-01-21
Fortinet: 32 entries (1.8% of all KEV entries are from this vendor); 9 added in 2026.
BOD 26-04 note: this is the date printed in the CISA catalog. A federal agency's actual deadline is set by its SSVC tier - Act (3 days), Attend (14 days), Track (60 days), or the next scheduled upgrade - counted from the KEV listing date or the date the vulnerability is identified in its environment, whichever comes first. Use the tier helper on each CVE page for your own window.
Your BOD 26-04 window (SSVC tier helper)
Your remediation window ends:
Description
Fortinet FortiOS and FortiProxy contain an authentication bypass vulnerability that may allow an unauthenticated, remote attacker to gain super-admin privileges via crafted requests to Node.js websocket module.
Required action (CISA)
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Notes
https://fortiguard.fortinet.com/psirt/FG-IR-24-535 ; https://nvd.nist.gov/vuln/detail/CVE-2024-55591
References
Other KEV entries for this vendor: Fortinet
- CVE-2025-61624 - Multiple Products (2026-10-16)
- CVE-2026-104286 - FortiMail (2026-10-01)
- CVE-2025-25249 - Multiple Products (2026-09-09)
- CVE-2025-68686 - FortiOS (2026-07-27)
- CVE-2026-25089 - FortiSandbox (2026-07-16)
- CVE-2026-39808 - FortiSandbox (2026-07-16)
- CVE-2026-21643 - FortiClient EMS (2026-04-13)
- CVE-2026-35616 - FortiClient EMS (2026-04-06)
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