What is CVE-2026-84393?

CVE-2026-84393 is a high-severity vulnerability in Fortinet Fortios, classified under Improper Validation of Certificate with Host Mismatch. CVSS score: 8.1/10. Published 2026-09-08.

How severe is CVE-2026-84393?

High severity. CVSS v3 base score is 8.1 out of 10.

Vulnerability in Fortinet Fortios

CVE-2026-84393

A improper validation of certificate with host mismatch vulnerability in Fortinet FortiOS 7.6.1 through 7.6.6, FortiProxy 7.6.2 through 7.6.6 may allow attacker to information disclosure via <insert attack vector here>

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Fortinet Fortios
Fortinet Fortiproxy

Weakness classification (CWE)

CWE-297 — Improper Validation of Certificate with Host Mismatch

References

psirt@fortinet.com

Frequently asked questions

What is CVE-2026-84393?: CVE-2026-84393 is a high-severity vulnerability in Fortinet Fortios, classified under Improper Validation of Certificate with Host Mismatch. CVSS score: 8.1/10. Published 2026-09-08.
How severe is CVE-2026-84393?: High severity. CVSS v3 base score is 8.1 out of 10.