CVE-2026-49798: Windows Kernel Elevation of Privilege Vulnerability

Overview

Severity

Critical (CVSS 9.3)

CVSS Vector

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/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-Jul

Released

2026-07-14

Description

Use after free in Windows Kernel allows an unauthorized 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. How could an attacker exploit this vulnerability? An attacker could run a specially crafted program on a local system that triggers the vulnerable function while a menu is being processed, causing the system to use memory that has already been freed. This can result in memory corruption, which an attacker may use to run malicious code.

Affected Products (27)

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

Security Updates (10)

• 5099538
• 5099540
• 5099539
• 5099536
• 5101650
• 5095051
• 5101649
• 5099535
• 5099445
• 5099444

Acknowledgments

Anonymous, <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, <a href="https://www.linkedin.com/in/p1nkjelly/">Minwoo Jeong (P1nkjelly)</a> with <a href="https://hacking.kaist.ac.kr/">KAIST Hacking Lab</a>

Revision History

• 2026-07-14: Information published.