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, 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.

Fortinet has observed in the wild exploitation of this vulnerability. Customers must upgrade to the latest versions in order to use FortiCloud SSO authentication

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, 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 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.

This plugin only works with Tenable.ot.
Please visit https://www.tenable.com/products/tenable-ot for more information.

The version of FortiWeb installed on the remote host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the FG-IR-26-060 advisory.

  - An Authentication Bypass Using an Alternate Path or Channel vulnerability [CWE-288] in FortiOS,     FortiManager, FortiAnalyzer 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. (CVE-2026-24858)

  - 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, 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. (CVE-2026-24858)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The version of FortiAnalyzer installed on the remote host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the FG-IR-26-060 advisory.

  - An Authentication Bypass Using an Alternate Path or Channel vulnerability [CWE-288] in FortiOS,     FortiManager, FortiAnalyzer 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. (CVE-2026-24858)

  - 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, 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. (CVE-2026-24858)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The version of FortiManager installed on the remote host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the FG-IR-26-060 advisory.

  - An Authentication Bypass Using an Alternate Path or Channel vulnerability [CWE-288] in FortiOS,     FortiManager, FortiAnalyzer 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. (CVE-2026-24858)

  - 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, 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. (CVE-2026-24858)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The version of Fortigate installed on the remote host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the FG-IR-26-060 advisory.

  - An Authentication Bypass Using an Alternate Path or Channel vulnerability [CWE-288] in FortiOS,     FortiManager, FortiAnalyzer 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. (CVE-2026-24858)

  - 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, 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. (CVE-2026-24858)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Severity
505269	Siemens APE1808 Authentication Bypass Using an Alternate Path or Channel (CVE-2026-24858)	Tenable OT Security	Tenable.ot	critical
297164	Fortinet FortiWeb SSO authentication bypass (FG-IR-26-060)	Nessus	Firewalls	critical
296981	Fortinet FortiAnalyzer SSO authentication bypass (FG-IR-26-060)	Nessus	Firewalls	critical
296980	Fortinet FortiManager SSO authentication bypass (FG-IR-26-060)	Nessus	Firewalls	critical
296979	Fortinet Fortigate SSO authentication bypass (FG-IR-26-060)	Nessus	Firewalls	critical

Detections

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CVE-2026-24858

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Tenable Plugins

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