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CVE-2026-24858: Fortinet Multiple Products Authentication Bypass Using an Alternate Path or Channel Vulnerability

CVE-2026-24858 is rated critical with a CVSS v3.1 base score of 9.8 and affects Fortinet Multiple Products, along with 1 other product in NVD’s configuration data. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available. CISA added it to its Known Exploited Vulnerabilities catalog on 2026-01-27, which means exploitation in the wild has been observed.

Vulnerability description

An Authentication Bypass Using an Alternate Path or Channel vulnerability [CWE-288] vulnerability in Fortinet FortiAnalyzer 7.6.0 through 7.6.5, FortiAnalyzer 7.4.0 through 7.4.9, FortiAnalyzer 7.2.0 through 7.2.11, FortiAnalyzer 7.0.0 through 7.0.15, FortiManager 7.6.0 through 7.6.5, FortiManager 7.4.0 through 7.4.9, FortiManager 7.2.0 through 7.2.11, FortiManager 7.0.0 through 7.0.15, FortiNAC-F 7.6.3 through 7.6.5, FortiOS 7.6.0 through 7.6.5, FortiOS 7.4.0 through 7.4.10, FortiOS 7.2.0 through 7.2.12, FortiOS 7.0.0 through 7.0.18, FortiProxy 7.6.0 through 7.6.4, FortiProxy 7.4.0 through 7.4.12, FortiProxy 7.2.0 through 7.2.15, FortiProxy 7.0.0 through 7.0.22, FortiWeb 8.0.0 through 8.0.3, FortiWeb 7.6.0 through 7.6.6, FortiWeb 7.4.0 through 7.4.11 may allow an attacker with a FortiCloud account and a registered device to log into other devices registered to other accounts, if FortiCloud SSO authentication is enabled on those devices.

Severity breakdown

CVSS v3.1 9.8: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

  • Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
  • Attack complexity: Low. No special conditions; the attack can be repeated reliably.
  • Privileges required: None. No account or prior access is needed.
  • User interaction: None. No action from any user is needed.
  • Scope: Unchanged. Impact stays within the vulnerable component.
  • Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
  • Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
  • Availability impact: High. Total loss of availability; the component can be shut down.

Underlying weakness

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

The product requires authentication, but the product has an alternate path or channel that does not require authentication.

Affected products

  • Fortinet Fortianalyzer: from 7.0.0 up to and including 7.0.15; from 7.2.0 up to and including 7.2.11; from 7.4.0 before 7.4.10; from 7.6.0 before 7.6.6
  • Fortinet Fortimanager: from 7.0.0 up to and including 7.0.15; from 7.2.0 up to and including 7.2.11; from 7.4.0 before 7.4.10; from 7.6.0 before 7.6.6
  • Fortinet Fortinac F: from 7.6.3 before 7.6.6
  • Fortinet Fortiproxy: from 7.0.0 up to and including 7.0.22; from 7.2.0 up to and including 7.2.15; from 7.4.0 up to and including 7.4.12; from 7.6.0 up to and including 7.6.4
  • Fortinet Fortiweb: from 7.4.0 up to and including 7.4.11; from 7.6.0 up to and including 7.6.6; from 8.0.0 up to and including 8.0.3
  • Fortinet Fortios: from 7.0.0 up to and including 7.0.18; from 7.2.0 up to and including 7.2.12; from 7.4.0 before 7.4.11; from 7.6.0 before 7.6.6
  • Siemens Ruggedcom Ape1808 Firmware: all versions listed by NVD

References