CVE-2026-83999

Severity CVSS v4.0:

Pending analysis

Type:

CWE-59 Link Following

Publication date:

08/09/2026

Last modified:

08/09/2026

Description

Improper link resolution before file access (&#39;link following&#39;) in Windows Resilient File System (ReFS) Deduplication Service allows an authorized attacker to elevate privileges locally.

Impact

Vector 3.x

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

Base Score: 7.00 HIGH
Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

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

Base Score 3.x

7.00

Severity 3.x

HIGH

References to Advisories, Solutions, and Tools

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83999