CVE-2026-56184: Win32k 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-Jul

Released

2026-07-14

Description

Exposure of sensitive information to an unauthorized actor in Windows Win32K allows an authorized attacker to disclose information locally.

FAQ

What type of information could be disclosed by this vulnerability? Exploiting this vulnerability could allow the disclosure of certain memory address within kernel space. Knowing the exact location of kernel memory could be potentially leveraged by an attacker for other malicious activities.

Affected Products (15)

Windows

• Windows Server 2022
• 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 25H2 for ARM64-based Systems
• Windows 11 Version 25H2 for x64-based Systems
• Windows 11 Version 24H2 for ARM64-based Systems
• Windows 11 Version 24H2 for x64-based Systems
• Windows Server 2025
• Windows 11 version 26H1 for x64-based Systems
• Windows 11 Version 26H1 for ARM64-based Systems

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

Security Updates (5)

• 5099540
• 5099539
• 5099536
• 5101650
• 5101649

Acknowledgments

<a href="https://mylostchristmas.tistory.com/20">Seung Chan Kim</a>

Revision History

• 2026-07-14: Information published.