CISA KEV entry
CVE-2026-24858Fortinet Multiple Products Authentication Bypass Using an Alternate Path or Channel Vulnerability
Fortinet Multiple Products. Added to the CISA Known Exploited Vulnerabilities catalogue on 27 January 2026.
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
- 2026-01-27
- Federal due date
- 2026-01-30 3 days after it was added; passed at the sync of 2026-11-05
- Known ransomware use
- Unknown
- Forensic triage (BOD 26-04)
- No
- CVSS
- 9.8 Critical CVSS 3.1, scored by psirt@fortinet.com
- EPSS
- 86.59% percentile 99.7, scored 2026-11-04
- CISA SSVC
- Exploitation active, automatable yes, technical impact total
- NVD status
- Analyzed published 2026-01-27
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, 3 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 FortiAnalyzer, FortiManager, FortiOS, and FortiProxy contain an authentication bypass using an alternate path or channel that could 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.
Required action
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Notes
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
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-26-060 Vendor Advisory
- https://www.fortinet.com/blog/psirt-blogs/analysis-of-sso-abuse-on-fortios Mitigation, Vendor Advisory
Links in CISA's notes
NVD details
- CWE (NVD)
- CWE-288 by psirt@fortinet.com
- 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
- 2026-06-17T10:23:43.040
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 (psirt@fortinet.com) | 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 2026-01-28 | 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.