CVE-2026-24858
Fortinet — Fortinet Multiple Products Authentication Bypass Using an Alternate Path or Channel Vulnerability
Fortinet · in CISA KEV since 2026-01-27
CISA federal deadline · Overdue by 9 monthsCISA KEVActively Exploited
86
EVRS 86 of 100 Immediate
Patch Immediately
Rank 356 of 2,960 tracked
Why it scores 86
Evidence available: 6 of 7 signalsListed in the CISA KEV catalog, and an EPSS probability of 0.858.
- CISA KEVApplied
- RansomwareDid not apply
- Vendor exploitationDid not apply
- EPSSApplied
- Microsoft Exploitability IndexNot applicable
- Pre-patch disclosureNo data
- KEV recencyDid not apply
- CVSSApplied
The band answers “how soon”, not “how bad”. No data for: Pre-patch disclosure. Why some signals show no data
Fix
No fixed version identified yetCISA required action
- 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
- www.fortinet.com/…/analysis-of-sso-abuse-on-fortios
- nvd.nist.gov/…/CVE-2026-24858
Evidence
Each value with its source| Measure | Value | Source |
|---|---|---|
| CVSS base scoreHow severe the flaw is in itself. It does not say how likely an attack is. | 9.8 | NVD |
| FIRST EPSSFIRST's estimate of the chance this is exploited in the next 30 days, and how that ranks against all CVEs. | 0.858 (99.73rd pctl) | FIRST EPSS |
| Actively exploitedWhether a source of record has confirmed attacks using it in the wild. | Confirmed | CISA KEV |
| Ransomware campaign useWhether CISA has seen ransomware operators use it. | Unknown or none | CISA KEV |
| CISA remediation deadlineThe date US federal agencies must have fixed or mitigated it. | 2026-01-30 · CISA federal deadline · Overdue by 9 months | CISA KEV |
Description
What CISA says to do
- 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
- www.fortinet.com/…/analysis-of-sso-abuse-on-fortios
- nvd.nist.gov/…/CVE-2026-24858
