CVE-2026-77499: 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 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 10.0.20348.5622Patch KB5122882 - 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 10.0.17763.9245Patch KB5122876
Event History
Frequently Asked Questions
What access does an attacker need to exploit this issue?
The issue is remotely exploitable over a network. It requires no privileges or user interaction, and the attacker is described as unauthorized.
What is the expected impact if exploitation succeeds?
Successful exploitation can deny service in Windows DHCP Server. The provided severity vector indicates availability impact only, 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 versions.