CVE-2026-21222: Windows Kernel Information Disclosure Vulnerability

Overview

Severity

Medium (CVSS 5.5)

CVSS Vector

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

Category

Information Disclosure

Exploit Status

Not Exploited

Exploitation Likelihood

Less Likely

Patch Tuesday

2026-Feb

Released

2026-02-10

EPSS Score

0.04% (percentile: 12.4%)

Description

Insertion of sensitive information into log file in Windows Kernel allows an authorized attacker to disclose information locally.

FAQ

What type of information could be disclosed by this vulnerability? The type of information that could be disclosed if an attacker successfully exploited this vulnerability is Kernel memory read - unintentional read access to memory contents in kernel space from a user mode process.

Affected Products (25)

Windows

• Windows 10 Version 1809 for 32-bit Systems
• Windows 10 Version 1809 for x64-based Systems
• Windows Server 2019
• Windows Server 2019 (Server Core installation)
• Windows Server 2022
• Windows Server 2022 (Server Core installation)
• Windows 10 Version 21H2 for 32-bit Systems
• Windows 10 Version 21H2 for ARM64-based Systems
• Windows 10 Version 21H2 for x64-based Systems
• Windows Server 2025 (Server Core installation)
• Windows 11 Version 23H2 for ARM64-based Systems
• Windows 11 Version 23H2 for x64-based Systems
• Windows Server 2022, 23H2 Edition (Server Core installation)
• Windows 11 Version 24H2 for ARM64-based Systems
• Windows 11 Version 24H2 for x64-based Systems
• Windows Server 2025
• Windows 10 Version 1607 for 32-bit Systems
• Windows 10 Version 1607 for x64-based Systems
• Windows Server 2016
• Windows Server 2016 (Server Core installation)

ESU

• Windows 10 Version 22H2 for x64-based Systems
• Windows 10 Version 22H2 for ARM64-based Systems
• Windows 10 Version 22H2 for 32-bit Systems
• Windows Server 2012 R2
• Windows Server 2012 R2 (Server Core installation)

Security Updates (12)

• 5075904
• 5075906
• 5075943
• 5075912
• 5075899
• 5075942
• 5075941
• 5075897
• 5077181
• 5077212
• 5075999
• 5075970

Acknowledgments

Microsoft Offensive Research & Security Engineering

Revision History

• 2026-02-10: Information published. This CVE was addressed by updates that were released in November 2025, but the CVE was inadvertently omitted from the November 2025 Security Updates. This is an informational change only. Customers who have already installed the November 2025 updates do not need to take any further action.