CVE-2026-33841: Windows Kernel Elevation of Privilege Vulnerability

Overview

Severity

High (CVSS 7.8)

CVSS Vector

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

Category

Elevation of Privilege

Exploit Status

Not Exploited

Exploitation Likelihood

More Likely

Patch Tuesday

2026-May

Released

2026-05-12

Description

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

FAQ

What privileges could be gained by an attacker who successfully exploited the vulnerability? An attacker could use this vulnerability to elevate privileges from a Low Integrity Level in a contained ("sandboxed") execution environment to a Medium Integrity Level or a High Integrity Level. Please refer to AppContainer isolation and Mandatory Integrity Control for more information.

Affected Products (19)

Windows

• 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 25H2 for ARM64-based Systems
• Windows 11 Version 25H2 for x64-based Systems
• 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 11 Version 26H1 for ARM64-based Systems
• Windows 11 Version 26H1 for x64-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 (10)

• 5087545
• 5087424
• 5087544
• 5087539
• 5087423
• 5089549
• 5089466
• 5087420
• 5087541
• 5089548

Acknowledgments

Anonymous, Andrew Fasano with <a href="https://nist.gov/caisi">NIST Center for AI Standards and Innovation</a>, Andrew Fasano with <a href="https://nist.gov/caisi">NIST Center for AI Standards and Innovation</a>, <a href="https://www.linkedin.com/in/p1nkjelly/">Minwoo Jeong (P1nkjelly)</a> with <a href="https://hacking.kaist.ac.kr/">KAIST Hacking Lab</a>, <a href="https://x.com/r0keb">r0keb</a> with <a href="https://calif.io/">Calif</a>, <a href="https://x.com/r0keb">r0keb</a> with <a href="https://calif.io/">Calif</a>

Revision History

• 2026-05-12: Information published.