CVE-2026-84386 Missing authorization in FortiClientWindows
An attacker can exploit an exposed minifilter communication port in FortiClient Windows to bypass access controls and potentially escalate privileges.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-84386?
CVE-2026-84386 is a medium-severity missing authorization vulnerability in Fortinet FortiClientWindows, published on 8 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
A unverified ownership vulnerability in Fortinet FortiClientWindows 7.4.0 through 7.4.7, FortiClientWindows 7.2 all versions may allow attacker to improper access control via via an exposed minifilter communication port.
Weakness: CWE-283
Which versions are affected by CVE-2026-84386?
How do I fix CVE-2026-84386?
No fix has been published for CVE-2026-84386 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-84386 being exploited?
There is no known exploitation of CVE-2026-84386 in the wild and no public exploit code.
Sources
Also known as GHSA-5g7q-39wf-m9fj.