Windows TCP/IP Elevation of Privilege Vulnerability
CVE-2026-42904

9.6CRITICAL

Key Information:

Vendor: Microsoft
Status: Windows 10 Version 21h2; Windows 10 Version 22h2; Windows 11 Version 23h2; Windows 11 Version 23h2
Vendor: CVE Published:; 9 June 2026

What is CVE-2026-42904?

Heap-based buffer overflow in Windows TCP/IP allows an unauthorized attacker to elevate privileges over an adjacent network.

Windows 10 Version 21H2 32-bit Systems 10.0.19044.0 < 10.0.19044.7417

Windows 10 Version 22H2 32-bit Systems 10.0.19045.0 < 10.0.19045.7417

Windows 11 version 23H2 ARM64-based Systems 10.0.22631.0 < 10.0.22631.7219

Score:

9.6

Severity:

CRITICAL

Confidentiality:

High

Integrity:

High

Availability:

High

Attack Vector:

Adjacent Network

Attack Complexity:

Low

Privileges Required:

None

User Interaction:

None

Scope:

Changed

Download the Critical Vulnerability Management Cheat Sheet

CVE-2026-42904 Data