ClosedCriticalPatched

Fortinet FortiOS and FortiProxy: FortiOS and FortiProxy Authentication Bypass Vulnerability

Fortinet FortiOS and FortiProxy

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. Added to CISA KEV on 2025-01-14.

Why this severity: CVSS 9.6 (CNA, v3.1); actively exploited (CISA KEV); known ransomware use

Started: Jan 14, 2025
Closed: Jan 14, 2025
CVE: CVE-2024-55591

Follow this incident

Updated Jan 14, 2025

Affected

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

Fixed in

See vendor advisory linked in sources

Timeline1

Jan 14, 2025
CISA added CVE-2024-55591 to the KEV catalog (due 2025-01-21).

Advisories3

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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