CVE-2026-77888: 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 10.0.14393.9512Patch KB5123099 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 6.2.9200.26349Patch KB5123065 - Upgrade
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Fixed in 10.0.20348.5622Patch KB5122882 - Upgrade
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Fixed in 10.0.26100.33438Patch KB5122871 - 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
Event History
Frequently Asked Questions
What access does an attacker need to exploit this issue?
The vulnerability is exploitable remotely over a network. It requires no authentication, no privileges, and no user interaction.
What is the expected impact if exploitation succeeds?
Successful exploitation can deny service in Windows DHCP Server. The available information identifies no confidentiality or integrity impact.
Which systems are listed as affected?
The affected software list includes Microsoft Windows 10 and Microsoft Windows Server 2012, Windows Server 2012 R2, Windows Server 2016, Windows Server 2019, Windows Server 2022, and Windows Server 2025.