Junglewise Threat Intelligence

CVE-2026-77889: Microsoft Windows DHCP Server type confusion denial of service

CVE-2026-77889 · Severity: high · CVSS 7.5 · Published 2026-09-08

Executive brief

Windows DHCP Server is a network service that assigns IP addresses to devices on corporate networks. A type confusion vulnerability allows an unauthenticated attacker to crash the DHCP service over the network, disrupting IP address allocation and potentially rendering network connectivity unavailable for affected devices.

Technical details

A type confusion vulnerability (CWE-843) in Windows DHCP Server allows an attacker to access memory resources using an incompatible type, triggering a denial of service condition. The vulnerability is network-reachable and requires no authentication or user interaction. An attacker can send a specially crafted DHCP message to crash the DHCP Server service, preventing legitimate clients from obtaining IP addresses. A patch is available from Microsoft.

Affected products

  • Microsoft Windows DHCP Server multiple versions

Timeline

  • 2026-09-08: disclosed

References

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