Feb 2026: Windows Kernel Elevation of Privilege Vulnerability
CVE-2026-21239 Published on February 10, 2026

Windows Kernel Elevation of Privilege Vulnerability
Heap-based buffer overflow in Windows Kernel allows an authorized attacker to elevate privileges locally.

Vendor Advisory NVD

Weakness Type

Heap-based Buffer Overflow

A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().

Products Associated with CVE-2026-21239

You can be notified by email with stack.watch whenever vulnerabilities like CVE-2026-21239 are published in these products:

Microsoft Windows 10

Microsoft Windows Server 2019

Microsoft Windows Server 2022

Microsoft Windows Server 2025

Microsoft Windows 11 25h2

Microsoft Windows 11 23h2

Microsoft Windows Server 23h2

Microsoft Windows 11 24h2

Microsoft Windows Server 2016

Microsoft Windows Server 2012

Microsoft Windows Server 2012 R2

Affected Versions

Microsoft Windows 10 Version 1607:

Version 10.0.14393.0 and below 10.0.14393.8868 is affected.

Microsoft Windows 10 Version 1809:

Version 10.0.17763.0 and below 10.0.17763.8389 is affected.

Microsoft Windows 10 Version 21H2:

Version 10.0.19044.0 and below 10.0.19044.6937 is affected.

Microsoft Windows 10 Version 22H2:

Version 10.0.19045.0 and below 10.0.19045.6937 is affected.

Microsoft Windows 11 version 22H3:

Version 10.0.22631.0 and below 10.0.22631.6649 is affected.

Microsoft Windows 11 Version 23H2:

Version 10.0.22631.0 and below 10.0.22631.6649 is affected.

Microsoft Windows 11 Version 24H2:

Version 10.0.26100.0 and below 10.0.26100.7840 is affected.

Microsoft Windows 11 Version 25H2:

Version 10.0.26200.0 and below 10.0.26200.7840 is affected.

Microsoft Windows Server 2012:

Version 6.2.9200.0 and below 6.2.9200.25923 is affected.

Microsoft Windows Server 2012 (Server Core installation):

Version 6.2.9200.0 and below 6.2.9200.25923 is affected.

Microsoft Windows Server 2012 R2:

Version 6.3.9600.0 and below 6.3.9600.23022 is affected.

Microsoft Windows Server 2012 R2 (Server Core installation):

Version 6.3.9600.0 and below 6.3.9600.23022 is affected.

Microsoft Windows Server 2016:

Version 10.0.14393.0 and below 10.0.14393.8868 is affected.

Microsoft Windows Server 2016 (Server Core installation):

Version 10.0.14393.0 and below 10.0.14393.8868 is affected.

Microsoft Windows Server 2019:

Version 10.0.17763.0 and below 10.0.17763.8389 is affected.

Microsoft Windows Server 2019 (Server Core installation):

Version 10.0.17763.0 and below 10.0.17763.8389 is affected.

Microsoft Windows Server 2022:

Version 10.0.20348.0 and below 10.0.20348.4773 is affected.

Microsoft Windows Server 2022, 23H2 Edition (Server Core installation):

Version 10.0.25398.0 and below 10.0.25398.2149 is affected.

Microsoft Windows Server 2025:

Version 10.0.26100.0 and below 10.0.26100.32370 is affected.

Microsoft Windows Server 2025 (Server Core installation):

Version 10.0.26100.0 and below 10.0.26100.32370 is affected.

Exploit Probability

EPSS

0.02%

Percentile

5.36%