Description
Access of resource using incompatible type ('type confusion') in Windows DHCP Server allows an unauthorized attacker to deny service over a network.
Published: 2026-09-08
Score: 7.5 High
EPSS: 1.2% Low
KEV: No
Impact: Denial of Service on Windows DHCP Server
Action: Apply Patch
AI Analysis

Impact

An attacker who can send specially crafted DHCP packets to a Windows DHCP Server can exploit a type confusion bug, causing the server to terminate or become unresponsive. This is a classic denial‑of‑service (DoS) vulnerability that can deny service to legitimate clients or disrupt network mobility. The weakness is identified as CWE‑843 (Type Confusion).

Affected Systems

Microsoft Windows 10 Version 1607, Windows 10 Version 1809, Windows Server 2012, Windows Server 2012 (R2), Windows Server 2016, Windows Server 2019, Windows Server 2022, and Windows Server 2025, including Server Core installations for each version.

Risk and Exploitability

The CVSS score of 7.5 indicates a high‑severity DoS risk. While the EPSS score is not available and the vulnerability is not listed in CISA KEV, the likelihood of exploitation remains significant for an attacker who can reach the target DHCP server over the network. The inferred attack vector is remote, requiring network access to send malformed DHCP packets to the vulnerable service.

Generated by OpenCVE AI on September 9, 2026 at 02:00 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Install the latest Windows update that addresses the DHCP server type confusion vulnerability.
  • If the system cannot be patched immediately, temporarily disable the DHCP service and re‑enable it after patching or replace the service with a third‑party DHCP server.
  • Monitor DHCP logs for crashes or frequent restarts, and investigate any anomalous DHCP traffic; apply firewall rules to block suspicious packets.
  • Verify that the DHCP service is not exposed to untrusted networks and consider segmenting DHCP traffic to reduce the attack surface.

Generated by OpenCVE AI on September 9, 2026 at 02:00 UTC.

Tracking

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Advisories

No advisories yet.

History

Wed, 16 Sep 2026 15:15:00 +0000

Type Values Removed Values Added
CPEs cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:*

Thu, 10 Sep 2026 21:30:00 +0000

Type Values Removed Values Added
First Time appeared Microsoft windows Server 2012 (server Core Installation)
Microsoft windows Server 2012 R2
Microsoft windows Server 2012 R2 (server Core Installation)
Microsoft windows Server 2016 (server Core Installation)
Microsoft windows Server 2019 (server Core Installation)
Microsoft windows Server 2025 (server Core Installation)
Vendors & Products Microsoft windows Server 2012 (server Core Installation)
Microsoft windows Server 2012 R2
Microsoft windows Server 2012 R2 (server Core Installation)
Microsoft windows Server 2016 (server Core Installation)
Microsoft windows Server 2019 (server Core Installation)
Microsoft windows Server 2025 (server Core Installation)

Tue, 08 Sep 2026 22:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Tue, 08 Sep 2026 17:30:00 +0000

Type Values Removed Values Added
Description Access of resource using incompatible type ('type confusion') in Windows DHCP Server allows an unauthorized attacker to deny service over a network.
Title Windows DHCP Server Denial of Service Vulnerability
First Time appeared Microsoft
Microsoft windows 10 1607
Microsoft windows 10 1809
Microsoft windows Server 2012
Microsoft windows Server 2012 R2
Microsoft windows Server 2016
Microsoft windows Server 2019
Microsoft windows Server 2022
Microsoft windows Server 2025
Weaknesses CWE-843
CPEs cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x86:*
cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x86:*
cpe:2.3:o:microsoft:windows_server_2012:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_server_2012_R2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*
Vendors & Products Microsoft
Microsoft windows 10 1607
Microsoft windows 10 1809
Microsoft windows Server 2012
Microsoft windows Server 2012 R2
Microsoft windows Server 2016
Microsoft windows Server 2019
Microsoft windows Server 2022
Microsoft windows Server 2025
References
Metrics cvssV3_1

{'score': 7.5, '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'}

Subscriptions

Microsoft Windows 10 1607 Windows 10 1809 Windows Server 2012 Windows Server 2012 (server Core Installation) Windows Server 2012 R2 Windows Server 2012 R2 Windows Server 2012 R2 (server Core Installation) Windows Server 2016 Windows Server 2016 (server Core Installation) Windows Server 2019 Windows Server 2019 (server Core Installation) Windows Server 2022 Windows Server 2025 Windows Server 2025 (server Core Installation)
cve-icon MITRE

Status: PUBLISHED

Assigner: microsoft

Published:

Updated: 2026-09-25T21:33:22.936Z

Reserved: 2026-08-21T17:26:55.612Z

Link: CVE-2026-77890

cve-icon Vulnrichment

Updated: 2026-09-08T20:53:01.679Z

cve-icon NVD

Status : Analyzed

Published: 2026-09-08T18:20:38.737

Modified: 2026-09-24T23:19:02.820

Link: CVE-2026-77890

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-10T21:05:52Z

Weaknesses
  • CWE-843

    Access of Resource Using Incompatible Type ('Type Confusion')