CVE-2026-70243: Windows Kernel Elevation of Privilege Vulnerability

Overview

Severity

High (CVSS 7)

CVSS Vector

CVSS:3.1/AV:L/AC:H/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-Oct

Released

2026-10-13

Description

Use after free 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. According to the CVSS metric, the attack complexity is high (AC:H). What does that mean for this vulnerability? Successful exploitation of this vulnerability requires an attacker to win a race condition.

Affected Products (4)

Windows

• Windows Server 2025 (Server Core installation)
• Windows 11 Version 23H2 for ARM64-based Systems
• Windows 11 Version 23H2 for x64-based Systems
• Windows Server 2025

Security Updates (2)

• 5126646
• 5126653

Acknowledgments

Byzero with Kunlun Lab & Zhiniang Peng with HUST

Revision History

• 2026-10-13: Information published.