CVE-2026-48566: Windows DWM Core Library 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-Jun

Released

2026-06-09

Last Updated

2026-06-09

Description

Out-of-bounds read in Windows DWM Core Library allows an authorized attacker to disclose information locally.

FAQ

What type of information could be disclosed by this vulnerability? An attacker who successfully exploited this vulnerability could potentially read small portions of heap memory.

Affected Products (8)

Windows

• 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

Security Updates (5)

• 5087539
• 5087423
• 5089549
• 5089466
• 5089548

Acknowledgments

namnp with <a href="https://x.com/vcslab">Viettel Cyber Security</a>

Revision History

• 2026-06-09: Information published.
• 2026-06-09: Information published. This CVE was addressed by updates that were released in May 2026, but the CVE was inadvertently omitted from the May 2026 Security Updates. This is an informational change only. Customers who have already installed the May 2026 updates do not need to take any further action.