CVE-2026-83991

Severity CVSS v4.0:

Pending analysis

Type:

CWE-306 Missing Authentication for Critical Function

Publication date:

08/09/2026

Last modified:

08/09/2026

Description

Missing authentication for critical function in Windows Cloud Files Mini Filter Driver allows an authorized attacker to perform tampering locally.

Impact

Vector 3.x

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N CVSS v3.1 Severity and Metrics:

Base Score: 5.50 MEDIUM
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

Attack Vector (AV): Local
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): None
Integrity (I): High
Availability (A): None

Base Score 3.x

5.50

Severity 3.x

MEDIUM

References to Advisories, Solutions, and Tools

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83991