CVE-2026-77890: Windows DHCP Server Denial of Service Vulnerability
Access of resource using incompatible type ('type confusion') in Windows DHCP Server allows an unauthorized attacker to deny service over a network.
Other sources
Windows DHCP Server Denial of Service Vulnerability
— Microsoft
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.17763.9245Patch KB5122876 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 6.3.9600.23397Patch KB5123066 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.14393.9512Patch KB5123099 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 6.2.9200.26349Patch KB5123065 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.26100.33438Patch KB5122871 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.20348.5622Patch KB5122882
Event History
Frequently Asked Questions
Who can exploit this issue?
An unauthorized attacker can exploit it remotely over a network. No privileges or user interaction are required.
What is the expected impact of a successful attack?
The stated impact is denial of service against Windows DHCP Server. The supplied scoring indicates high availability impact, with no stated confidentiality or integrity impact.
Which systems should be prioritized for review?
Review systems running Windows DHCP Server on the listed Microsoft Windows 10, Windows Server 2012, 2012 R2, 2016, 2019, 2022, or 2025 platforms. The provided data does not identify specific affected builds or patch levels.