CVE-2026-84393: Information disclosure in Fortinet FortiOS
Description
CVE-2026-84393 is a high severity vulnerability in Fortinet FortiOS and FortiProxy versions 7.6.1 through 7.6.6. It involves improper validation of certificates with host mismatches, which may allow an attacker to cause information disclosure. The vulnerability has a CVSS score of 7.3 and has an official fix available.
CVSS v3.1
Score 7.3high
Affected software
Fortinet
FortiOS
Fortinet
FortiProxy
cpe:2.3:a:fortinet:fortiproxy:7.6.6:*:*:*:*:*:*:*cpe:2.3:a:fortinet:fortiproxy:7.6.5:*:*:*:*:*:*:*cpe:2.3:a:fortinet:fortiproxy:7.6.4:*:*:*:*:*:*:*cpe:2.3:a:fortinet:fortiproxy:7.6.3:*:*:*:*:*:*:*cpe:2.3:a:fortinet:fortiproxy:7.6.2:*:*:*:*:*:*:*AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability in Fortinet FortiOS (versions 7.6.1 to 7.6.6) and FortiProxy (versions 7.6.2 to 7.6.6) is due to improper validation of certificates when there is a host mismatch. This flaw can be exploited by an attacker to disclose sensitive information. The CVSS 3.1 base score is 7.3, indicating high severity, with network attack vector, high attack complexity, no privileges or user interaction required, and impacts confidentiality, integrity, and availability. An official fix is available from the vendor.
Potential Impact
Successful exploitation of this vulnerability can lead to disclosure of sensitive information due to improper certificate validation. The vulnerability affects confidentiality, integrity, and availability, as indicated by the CVSS vector. There are no known exploits in the wild at this time.
Mitigation Recommendations
An official fix is available for this vulnerability. It is recommended to apply the vendor-provided patches for FortiOS versions 7.6.1 through 7.6.6 and FortiProxy versions 7.6.2 through 7.6.6 to remediate this issue.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- fortinet
- Date Reserved
- 2026-09-01T16:36:14.802Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- official-fix
Threat ID: 6aa03d6cacd9273b49f0b442
Added to database: 09/08/2026, 16:53:00 UTC
Last enriched: 10/15/2026, 19:32:22 UTC
Last updated: 10/16/2026, 06:48:19 UTC
Views: 295
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