What is CVE-2024-55591?

CVE-2024-55591 is a critical-severity vulnerability in Fortinet Fortios, classified under Authentication Bypass Using an Alternate Path or Channel. CVSS score: 9.8/10. Published 2025-01-14.

How severe is CVE-2024-55591?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Is CVE-2024-55591 known to be exploited?

Yes. CVE-2024-55591 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2025-01-14), indicating it is being actively exploited. 27 public proof-of-concept repositories are indexed.

Vulnerability in Fortinet Fortios

CVE-2024-55591

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.

Published 2025-01-14 · last modified 2026-08-05.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.941 (99.8th percentile), scored 2026-10-15.

High probability of exploitation in the next 30 days — patch promptly. 100th percentile — 99.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.983 · newest: 0.941 · change: -0.041

Affected products

Fortinet Fortios — versions 7.0.0
Fortinet Fortiproxy — versions 7.2.0, 7.0.0

Weakness classification (CWE)

CWE-288 — Authentication Bypass Using an Alternate Path or Channel

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on 2025-01-14. CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: 2025-01-21.

Required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Known ransomware campaign use: yes.

Public proof-of-concept exploits

References

fortiguard.fortinet.com/psirt/FG-IR-24-535 (Mitigation, Vendor Advisory)
134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)

Frequently asked questions

What is CVE-2024-55591?: CVE-2024-55591 is a critical-severity vulnerability in Fortinet Fortios, classified under Authentication Bypass Using an Alternate Path or Channel. CVSS score: 9.8/10. Published 2025-01-14.
How severe is CVE-2024-55591?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2024-55591 known to be exploited?: Yes. CVE-2024-55591 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2025-01-14), indicating it is being actively exploited. 27 public proof-of-concept repositories are indexed.