CVE-2024-55591 Fortinet FortiOS and FortiProxy Authentication Bypass Vulnerability
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.
From the CISA KEV catalogue version 2026.11.06, with Cybergen analysis. Updated 6 Nov 2026.
Should You Worry?
- CISA confirmed exploitation in the wild and added it to the Known Exploited Vulnerabilities catalogue on 14 Jan 2025.
- CISA lists it as known to be used in ransomware campaigns.
- Rated Critical severity (CVSS 9.6, scored by Vendor).
- This product type is often exposed to the internet, which is where attackers scan for it first.
- Named in Cybergen threat actor reporting: NightSpire, Qilin, The Gentlemen.
- It has been in the catalogue for 661 days. Systems still unpatched now have almost certainly been scanned for it.
What It Is
An Authentication Bypass Using an Alternate Path or Channel vulnerability [CWE-288] affecting FortiOS version 7.0.0 through 7.0.16 and FortiProxy version 7.0.0 through 7.0.19 and 7.2.0 through 7.2.12 allows a remote attacker to gain super-admin privileges via crafted requests to Node.js websocket module.
Affected Versions
| Product | Versions |
|---|---|
| Fortinet FortiOS | 7.0.0 to 7.0.16 |
| Fortinet FortiProxy | 7.2.0 to 7.2.12 7.0.0 to 7.0.19 |
From the public CVE record, as supplied by the vendor. Always confirm against the vendor advisory.
What To Do Now
- 1
Find it
Search your asset inventory and external attack surface for Fortinet FortiOS and FortiProxy. Include cloud images, appliances and anything a supplier runs for you.
Attack Surface Management - 2
Fix it
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Vulnerability Management - 3
Hunt for compromise
If an affected system was reachable before you patched, assume it may have been hit. Check logs, new accounts, web shells and outbound connections from the date of exposure.
Incident Response - 4
Prove it is fixed
Rescan or test the system after patching. Upgrades that fail silently and forgotten secondary instances are common.
Penetration Testing
The Compliance Clock
General guidance, not legal advice. Your obligations depend on your sector, scope and jurisdiction.
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