Improper Certificate Validation Vulnerability in Fortinet FortiOS and FortiProxy
CVE-2026-84393

7.3HIGH

Key Information:

Vendor

Fortinet
Status
FortiOS
Fortiproxy
Vendor
CVE Published:
8 September 2026

What is CVE-2026-84393?

An improper validation of certificates with host mismatches in Fortinet FortiOS and FortiProxy could allow an attacker to potentially disclose sensitive information. This occurs due to flaws in the certificate validation logic, which can be exploited under certain conditions when connecting to affected versions. Proper security measures should be taken to mitigate the risk associated with this vulnerability.

Affected Version(s)

FortiOS 7.6.1 <= 7.6.6

FortiProxy 7.6.2 <= 7.6.6

References

https://fortiguard.fortinet.com/psirt/FG-IR-26-174

CVSS V3.1

Score:
7.3
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
High
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.