CVE-2026-77890: CWE-843: Access of Resource Using Incompatible Type ('Type Confusion') in Microsoft Windows 10 Version 1607
Description
Access of resource using incompatible type ('type confusion') in Windows DHCP Server allows an unauthorized attacker to deny service over a network.
CVSS v3.1
Score 7.5high
Affected software
Microsoft
Windows 10 Version 1607
Microsoft
Windows 10 Version 1809
Microsoft
Windows Server 2012
Microsoft
Windows Server 2012 (Server Core installation)
Microsoft
Windows Server 2012 R2
Microsoft
Windows Server 2012 R2 (Server Core installation)
Microsoft
Windows Server 2016
Microsoft
Windows Server 2016 (Server Core installation)
Microsoft
Windows Server 2019
Microsoft
Windows Server 2019 (Server Core installation)
Microsoft
Windows Server 2022
Microsoft
Windows Server 2025
Microsoft
Windows Server 2025 (Server Core installation)
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability, identified as CVE-2026-77890, involves an access of resource using incompatible type (type confusion) in the Windows DHCP Server component. The flaw can be exploited by an unauthorized attacker to cause a denial of service condition over the network. It affects several Windows versions including Windows 10 Version 1607 and others as specified. The CVSS v3.1 base score is 7.5, indicating high severity. Microsoft has released an official fix for this vulnerability.
Potential Impact
An attacker can exploit this type confusion vulnerability in the Windows DHCP Server to cause a denial of service, disrupting network services. There is no impact on confidentiality or integrity according to the CVSS vector. No known exploits are reported in the wild at this time.
Mitigation Recommendations
An official fix is available from Microsoft. Users and administrators should apply the security updates provided by Microsoft for the affected Windows versions as detailed in the Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-77890.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2026-08-21T17:26:55.612Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- official-fix
- Vendor Advisory Urls
- [{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-77890","vendor":"Microsoft"}]
Threat ID: 6aa0455aacd9273b49fa9fda
Added to database: 09/08/2026, 17:26:50 UTC
Last enriched: 10/14/2026, 21:58:07 UTC
Last updated: 10/22/2026, 01:15:26 UTC
Views: 30
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