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Microsoft Security Response CenterCVE-2026-69781

Windows DHCP Client Denial of Service Vulnerability

Severity not listedVendor CVSS 6.5 / 10 1 CVE Published Sep 8, 2026 at 7:00 AM UTC

Summary

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

Products covered

A separate affected-products list was not included in the collected bulletin.

Remediation

Install KB5122871. Install KB5124008. Install KB5124012.

CVEs in this advisory 1

Update history

What changed in later vendor updates

SecurityAlert records field-level changes from the point we begin following a bulletin. Earlier vendor changes may not have a field-by-field record.

    • Severity changed from High to Unknown.
    • Removed affected products: Windows 11 Version 24H2 for ARM64-based Systems, Windows 11 Version 24H2 for x64-based Systems, Windows 11 Version 25H2 for ARM64-based Systems, Windows 11 Version 25H2 for x64-based Systems, Windows 11 Version 26H1 for....
    • Removed fixed versions: 10.0.26100.9445, 10.0.26100.33438, 10.0.26200.9445, 10.0.28000.2954.

Updates

  1. Published by Microsoft Security Response Center

    The publication date reported by the vendor.

  2. Added to SecurityAlert

    We collected the advisory from the official source.

  3. Confirmed at the source

    Our collector saw this advisory during a later source check.