CVE-2026-24858
Fortinet Multiple Products Authentication Bypass Using an Alternate Path or Channel Vulnerability
Does this matter?
Known to be exploited in the wild (CISA KEV, CISA remediation deadline 30 January 2026). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.
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.
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 86.09% probability · 100th percentile
- CISA KEV
- Listed 27 January 2026 · due 30 January 2026
- Weakness
- CWE-288
- Affected
- fortinet/fortianalyzer · fortinet/fortimanager · fortinet/fortinac-f · fortinet/fortiproxy · fortinet/fortiweb · fortinet/fortios · siemens/ruggedcom ape1808 firmware
- Source
- psirt@fortinet.com
CISA notes
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. Please adhere to Fortinet's guidelines to assess exposure and mitigate risks. Check for signs of potential compromise on all internet accessible Fortinet products affected by this vulnerability. Apply any final mitigations provided by the vendor as soon as they become available. For more information please see: https://fortiguard.fortinet.com/psirt/FG-IR-26-060 ; https://www.fortinet.com/blog/psirt-blogs/analysis-of-sso-abuse-on-fortios ; https://nvd.nist.gov/vuln/detail/CVE-2026-24858
References
- https://fortiguard.fortinet.com/psirt/FG-IR-26-060Vendor Advisory
- https://cert-portal.siemens.com/productcert/html/ssa-975644.htmlThird Party Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-24858US Government Resource
- https://www.fortinet.com/blog/psirt-blogs/analysis-of-sso-abuse-on-fortiosMitigation, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.