CVSS 3.1
8.1 highCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:HCVE-2026-121528 fortinet fortios: Improper Certificate Validation
High (8.1) in fortinet fortios. EPSS 0.2% estimated probability of exploitation activity in the next 30 days.
On this page
A improper certificate validation vulnerability in Fortinet FortiOS 7.6.0 through 7.6.4, FortiOS 7.4.0 through 7.4.9, FortiOS 7.2.0 through 7.2.13, FortiOS 7.0 all versions, FortiOS 6.4 all versions may allow a remote and unauthenticated attacker to perform a Man-in-the-Middle attack on the communication channel between the SSLVPN web portal and the backend destination website.
Severity
- EPSS
- 0.2% estimated probability of exploitation activity in the next 30 days; 16th percentile. Scored 2026-11-13. A forecast for this CVE across the internet, not for your own systems.
- CWE
- CWE-295 Improper Certificate Validation
- OWASP Top 10
- A07:2025 Authentication Failures
- Published
- Modified
- Assigned by
- fortinet (CNA)
- NVD analysis
- Awaiting analysis
- Record from
- the NVD, synced
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Affected
Versions
From the CNA's record in the CVE List.
| Product | Affected |
|---|---|
| Fortinet FortiOS | from 7.6.0 through 7.6.4 |
| Fortinet FortiOS | from 7.4.0 through 7.4.9 |
| Fortinet FortiOS | from 7.2.0 through 7.2.13 |
| Fortinet FortiOS | from 7.0.0 through 7.0.19 |
| Fortinet FortiOS | from 6.4.0 through 6.4.16 |
Attack patterns (CAPEC)
- CAPEC-459 Creating a Rogue Certification Authority Certificate Likelihood: Medium · Severity: Very High
- CAPEC-475 Signature Spoofing by Improper Validation Likelihood: Low · Severity: High
The attack patterns MITRE's CAPEC relates to this record's weaknesses, as MITRE names them. Credits.
History
- Score 7.7 → 8.1 high
Changes since this site first stored the record. The same for every record: /api/public/changes.