CVE-2026-77886: Windows DHCP Server Denial of Service Vulnerability
Out-of-bounds read 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 6.2.9200.26349Patch KB5123065 - 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 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?
An attacker can exploit the vulnerability over the network without authentication, privileges, or user interaction. The reported impact is denial of service against Windows DHCP Server.
Which systems should be assessed first?
Assess systems running the Windows DHCP Server role on the listed Microsoft Windows versions: Windows 10, Windows Server 2012, 2012 R2, 2016, 2019, 2022, and 2025. Systems not running DHCP Server are not identified in the provided data as affected.