Heap-based buffer overflow in Microsoft Windows and Windows Server - CVE-2026-83895

Vulnerability details

The vulnerability allows an attacker with physical access to system to escalate privileges to SYSTEM.

The vulnerability exists due to a heap-based buffer overflow in the Windows Win32 Kernel Subsystem when the subsystem is targeted through a physical attack. An attacker with physical access to system can exploit the overflow through physical access to escalate privileges to SYSTEM.

Affected software

How to mitigate CVE-2026-83895

External References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-83895

Related Security Bulletins

• Multiple vulnerabilities in Microsoft Windows