CVE-2026-35420: 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

Less 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 this vulnerability? An attacker who successfully exploited this vulnerability could gain SYSTEM privileges.

Affected Products (13)

Windows

• Windows Server 2019
• Windows Server 2019 (Server Core installation)
• Windows Server 2022
• Windows Server 2022 (Server Core installation)
• Windows Server 2025 (Server Core installation)
• Windows Server 2022, 23H2 Edition (Server Core installation)
• Windows Server 2025
• Windows Server 2016
• Windows Server 2016 (Server Core installation)

ESU

• Windows Server 2012
• Windows Server 2012 (Server Core installation)
• Windows Server 2012 R2
• Windows Server 2012 R2 (Server Core installation)

Security Updates (9)

• 5087538
• 5087545
• 5087424
• 5087539
• 5087423
• 5087541
• 5087537
• 5087470
• 5087471

Acknowledgments

<a href="https://linkedin.com/in/jongseongkim">Jongseong Kim (nevul37), SEC-agent team</a>, <a href="https://linkedin.com/in/hwiwonlee">Hwiwon Lee (hwiwonl), SEC-agent team</a>, Younggi Park (grill66), SEC-agent team

Revision History

• 2026-05-12: Information published.