MSRC-CVE-2026-69777 — Windows DHCP Client Elevation of Privilege Vulnerability

Summary

Impact: Elevation of Privilege. Microsoft rating: Important. Not known to be exploited — Exploitation More Likely. Customer action: Required.

Details

What privileges could be gained by an attacker who successfully exploited the vulnerability?
An attacker could use this vulnerability to elevate privileges from Medium Integrity Level to Local Service.

Security updates
10.0.26200.9445 — https://support.microsoft.com/help/5124008
10.0.28000.2954 — https://support.microsoft.com/help/5124012

Vulnerabilities 1

High 8.0

CVE-2026-69777

Windows DHCP Client Elevation of Privilege Vulnerability

Heap-based buffer overflow in Windows DHCP Client allows an authorized attacker to elevate privileges over an adjacent network.

Microsoft Windows 11 Version 24H2 Windows 11 Version 25H2 Windows 11 version 26H1 Windows

Sep 8, 2026

Revision history

2026-09-09 #2
Updated an acknowledgement. This is an informational change only.
2026-09-08 #1
Information published.

References

CVE-2026-69777 Windows DHCP Client Elevation of Privilege Vulnerability - HTML
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-69777
Microsoft Exploitability Index
https://www.microsoft.com/en-us/msrc/exploitability-index?rtc=1
Microsoft Support Lifecycle
https://support.microsoft.com/lifecycle
Common Vulnerability Scoring System
https://www.first.org/cvss