CVE-2026-77499: 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 (CVE-2026-77499) is a type confusion issue (CWE-843) in the Windows DHCP Server component affecting multiple Windows versions including Windows 10 Version 1607 and others. The flaw allows an attacker without privileges or user interaction to cause a denial of service condition remotely by accessing a resource using an incompatible type. The CVSS 3.1 base score is 7.5, reflecting network attack vector, low attack complexity, no privileges required, no user interaction, and an impact limited to availability. Microsoft has published an official fix for this vulnerability.
Potential Impact
An attacker can remotely cause a denial of service on affected Windows systems by exploiting the type confusion vulnerability in the DHCP Server. There is no impact on confidentiality or integrity. The denial of service could disrupt network services relying on DHCP.
Mitigation Recommendations
An official fix is available from Microsoft. Users and administrators should apply the security update provided in the Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-77499 to remediate this vulnerability.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2026-08-20T20:11:33.673Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- official-fix
- Vendor Advisory Urls
- [{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-77499","vendor":"Microsoft"}]
Threat ID: 6aa04558acd9273b49fa9ee9
Added to database: 09/08/2026, 17:26:48 UTC
Last enriched: 10/14/2026, 21:57:10 UTC
Last updated: 10/21/2026, 13:40:31 UTC
Views: 32
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
External Links
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.