Description
Improper authentication in Windows DHCP Server allows an authorized attacker to bypass a security feature locally.
Published: 2026-10-13
Score: 5.5 Medium
EPSS: < 1% Very Low
KEV: No
Impact: Local Security Feature Bypass
Action: Apply Patch
AI Analysis

Impact

The vulnerability is an improper authentication flaw in the Windows DHCP Server. An attacker who already has authorized local access can use this flaw to bypass a built‑in security feature on the host. The bypass can potentially allow modification of DHCP configurations or disable safeguards that protect the network traffic. The weakness is classified as CWE‑288 related to improper authorization.

Affected Systems

Affected products include Microsoft Windows 10, versions 1607 and 1809, and Windows Server from 2012 through 2025 in both standard and Server Core deployments. The broad operating system coverage means that any environment running a DHCP service on these platforms could be impacted if the service is running on an unpatched system.

Risk and Exploitability

The CVSS base score of 5.5 indicates moderate severity. A local attacker with authorized credentials could exploit the vulnerability; remote exploitation is not supported according to the description. The EPSS score is not available, and the vulnerability is not currently listed in the CISA KEV catalog, implying limited known exploitation activity. Administrators should evaluate the risk based on the presence of authorized users on the host and consider mitigating or patching accordingly.

Generated by OpenCVE AI on October 16, 2026 at 23:54 UTC.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Apply the latest Microsoft security update for Windows DHCP Server that addresses CVE-2026-85865.
  • Restrict local account permissions that manage DHCP to the minimum required, preventing accidental privilege misuse.
  • Enable DHCP service auditing and monitor logs for unauthorized configuration changes.

Generated by OpenCVE AI on October 16, 2026 at 23:54 UTC.

Tracking

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Advisories

No advisories yet.

History

Thu, 29 Oct 2026 19:30:00 +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:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:x64:*

Fri, 23 Oct 2026 17:30:00 +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)

Wed, 14 Oct 2026 19:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 13 Oct 2026 19:15:00 +0000

Type Values Removed Values Added
Description Improper authentication in Windows DHCP Server allows an authorized attacker to bypass a security feature locally.
Title Windows DHCP Server Security Feature Bypass 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-288
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': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N/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: 2026-10-31T18:05:07.423Z

Reserved: 2026-09-04T18:15:10.739Z

Link: CVE-2026-85865

cve-icon Vulnrichment

Updated: 2026-10-13T22:19:15.343Z

cve-icon NVD

Status : Analyzed

Published: 2026-10-13T19:21:13.410

Modified: 2026-10-29T19:24:29.230

Link: CVE-2026-85865

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-23T17:15:06Z

Weaknesses
  • CWE-288

    Authentication Bypass Using an Alternate Path or Channel