CVE-2026-83656 Windows Modern Device Management (MDM) Tampering Vulnerability
An authorized local attacker can tamper with Windows Modern Device Management due to missing authentication for critical functions.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-83656?
CVE-2026-83656 is a medium-severity missing authorization vulnerability in Microsoft Windows 10 21h2, published on 13 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
Missing authentication for critical function in Windows Modern Device Management (MDM) allows an authorized attacker to perform tampering locally.
Weakness: CWE-306
Which versions are affected by CVE-2026-83656?
It affects 9 products.
Products include Microsoft Windows 10 21h2, Microsoft Windows 10 22h2, Microsoft Windows 11 23h2, Microsoft Windows 11 24h2, Microsoft Windows 11 25h2, Microsoft Windows 11 26h1 and 3 more.
How do I fix CVE-2026-83656?
No fix has been published for CVE-2026-83656 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-2026-83656 being exploited?
There is no known exploitation of CVE-2026-83656 in the wild and no public exploit code.
Other vulnerabilities in Microsoft Windows 10 21h2
- CVE-2025-21333 Microsoft Windows Hyper-V NT Kernel Integration VSP Heap-based Buffer Overflow
- CVE-2025-21334 Microsoft Windows Hyper-V NT Kernel Integration VSP Use-After-Free
- CVE-2025-21335 Microsoft Windows Hyper-V NT Kernel Integration VSP Use-After-Free
- CVE-2026-42904 Windows TCP/IP Elevation of Privilege Vulnerability
- CVE-2026-105733 Windows Hyper-V Remote Code Execution Vulnerability
Sources
Also known as GHSA-r76h-ph6c-9jvj.