CVE-2026-70065: Windows DHCP Server Denial of Service Vulnerability

Overview

Severity

High (CVSS 7.5)

CVSS Vector

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

Category

Denial of Service

Exploit Status

Not Exploited

Exploitation Likelihood

Unlikely

Patch Tuesday

2026-Sep

Released

2026-09-08

Last Updated

2026-10-07

EPSS Score

1.17% (percentile: 67.3%)

Description

Missing release of memory after effective lifetime in Windows DHCP Server allows an unauthorized attacker to deny service over a network.

Affected Products (16)

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 Server 2022 (Server Core installation)
• Windows Server 2025 (Server Core installation)
• Windows Server 2025
• 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 Server 2012
• Windows Server 2012 (Server Core installation)
• Windows Server 2012 R2
• Windows Server 2012 R2 (Server Core installation)

Security Updates (6)

• 5122876
• 5122882
• 5122871
• 5123099
• 5123065
• 5123066

Acknowledgments

<a href="https://mylostchristmas.tistory.com/20">Seung Chan Kim</a>, sabersauce

Revision History

• 2026-09-08: Information published.
• 2026-10-07: Updated an acknowledgement. This is an informational change only.