CISA KEV entry
CVE-2024-55591Fortinet FortiOS and FortiProxy Authentication Bypass Vulnerability
Fortinet FortiOS and FortiProxy. Added to the CISA Known Exploited Vulnerabilities catalogue on 14 January 2025.
Data status: a source is stale
Last synced CISA catalogue version 2026.11.04 (released 4 November 2026) 1,768 entries Updated manually
- Date added
- 2025-01-14
- Federal due date
- 2025-01-21 7 days after it was added; passed at the sync of 2026-11-05
- Known ransomware use
- Known
- Forensic triage (BOD 26-04)
- No
- CVSS
- 9.8 Critical CVSS 3.1, scored by nvd@nist.gov
- EPSS
- 94.35% percentile 99.8, scored 2026-11-04
- CISA SSVC
- Exploitation active, automatable yes, technical impact total
- NVD status
- Analyzed published 2025-01-14
BOD 26-04 remediation window
With CISA's SSVC answers for this CVE (automatable: yes, technical impact: total), BOD 26-04 Table 1 gives 3 days and forensic triage on a publicly exposed asset (row 1) and 3 days and forensic triage on an asset that is not publicly exposed (row 9) S06. The catalogue due date, 7 days after the date added, was set before BOD 26-04 took effect on 10 June 2026 S06. The directive binds US federal civilian executive branch agencies only.
What CISA says
Short 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
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
CWE in the catalogue
CWE-288
Official links
- CISA KEV catalogue entry cisa.gov
- NVD record nvd.nist.gov
Vendor advisory and patch links
References NVD tags Vendor Advisory or Patch, exactly as NVD lists them.
- https://fortiguard.fortinet.com/psirt/FG-IR-24-535 Mitigation, Vendor Advisory
Links in CISA's notes
NVD details
- CWE (NVD)
- CWE-288 by psirt@fortinet.com, NVD-CWE-Other by nvd@nist.gov
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H- CVSS versions in NVD
- V31
- Last modified in NVD
- 2026-08-05T05:16:42.380
Where each value comes from
| Field | Source | Fetched, UTC | State |
|---|---|---|---|
| Catalogue fields | CISA KEV JSON, version 2026.11.04 | 2026-11-05 11:38 | current |
| NVD published, status, CVSS, CWE, vendor links | NVD CVE API 2.0; CVSS: NVD (nvd@nist.gov) | 2026-11-03 12:37 | current at 2026-11-05 11:38 |
| EPSS | FIRST EPSS API, scores of 2026-11-04 | 2026-11-05 11:38 | current |
| CISA SSVC | CISA ADP (via NVD), record of 2025-01-22 | 2026-11-03 12:37 | current |
This product uses data from the NVD API but is not endorsed or certified by the NVD. CISA does not endorse Sysprobs. Methodology.