CVE-2026-83656: Windows Modern Device Management (MDM) Tampering Vulnerability

Overview

Severity

Medium (CVSS 4.7)

CVSS Vector

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C

Category

Tampering

Exploit Status

Not Exploited

Exploitation Likelihood

Less Likely

Patch Tuesday

2026-Oct

Released

2026-10-13

Description

Missing authentication for critical function in Windows Modern Device Management (MDM) allows an authorized attacker to perform tampering locally.

FAQ

According to the CVSS metric, the attack complexity is high (AC:H). What does that mean for this vulnerability? Successful exploitation of this vulnerability requires an attacker to win a race condition.

Affected Products (20)

Windows

• Windows 10 Version 21H2 for 32-bit Systems
• Windows Server 2022
• Windows Server 2022 (Server Core installation)
• Windows 11 Version 23H2 for ARM64-based Systems
• Windows 11 Version 25H2 for ARM64-based Systems
• Windows 10 Version 21H2 for ARM64-based Systems
• Windows 10 Version 21H2 for x64-based Systems
• Windows 11 Version 23H2 for x64-based Systems
• Windows 11 Version 24H2 for ARM64-based Systems
• Windows 11 Version 24H2 for x64-based Systems
• Windows 11 Version 25H2 for x64-based Systems
• Windows Server 2025
• Windows Server 2025 (Server Core installation)
• Windows 11 Version 26H1 for ARM64-based Systems
• Windows 11 version 26H1 for x64-based Systems
• Windows 11 Version 26H2 for ARM64-based Systems
• Windows 11 Version 26H2 for x64-based Systems

ESU

• Windows 10 Version 22H2 for 32-bit Systems
• Windows 10 Version 22H2 for ARM64-based Systems
• Windows 10 Version 22H2 for x64-based Systems

Security Updates (6)

• 5126657
• 5126655
• 5126653
• 5127648
• 5126646
• 5127646

Acknowledgments

haowei yan & xiaozun tang

Revision History

• 2026-10-13: Information published.