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Weekly Signal
Live intelligence Updated 19 Aug 2026 · 12:58 UTC

Fortinet · Fortios, FortiOS and FortiProxy, Fortiproxy

CVE-2024-55591

Fortinet FortiOS and FortiProxy Authentication Bypass Vulnerability

Recommended action

Treat this as an immediate remediation priority. Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

View response plan
CVSS9.8
EPSS98.3%
KEVYes
ExploitationConfirmed exploitation
PatchPatch or guidance available ↓

Assessment

Why it matters

CISA lists this vulnerability as known to be exploited; exploitation is confirmed; EPSS is 98.3%; technical severity is CVSS 9.8.

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.

Who should care

  • Teams operating Fortios, FortiOS and FortiProxy, Fortiproxy
  • Vulnerability and exposure management teams
  • Security operations teams monitoring exploitation activity

Response plan

What I would do

  1. Confirm whether Fortios, FortiOS and FortiProxy, Fortiproxy is present in the environment.
  2. Identify affected versions and establish whether vulnerable services are exposed or reachable.
  3. Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
  4. Review relevant security telemetry for evidence of attempted or successful exploitation.
  5. Document the remediation decision and track it to verified completion.

Vendor remediation

Patch and remediation links

Use the vendor source below to confirm the correct fixed version, package or mitigation for your affected product.

Technical details

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE
CWE-288
Affected versions
Fortinet Fortios (Start Including: 7.0.0, End Excluding: 7.0.17); Fortinet FortiOS and FortiProxy; Fortinet Fortiproxy (Start Including: 7.2.0, End Excluding: 7.2.13)
Published
14 January 2025
Attack vector
Network
Privileges required
None
User interaction
None

Signal timeline

  1. CVE published
  2. Added to CISA KEV
  3. Latest EPSS score: 98.3%
  4. Signal calculated at 88

External references

Live public intelligence This assessment combines public-source evidence. Validate the affected product, version and exposure against your own environment before making a risk decision.