CVE-2026-69782

CVE-2026-69782 is a race condition (CWE-362) in Microsoft's DNS Server that leads to a use-after-free condition (CWE-416), allowing an unauthenticated remote attacker to execute arbitrary code by sending network traffic that triggers concurrent access to a shared resource. Exploitation requires no privileges or user interaction, but the high-attack-complexity score (AC:H) indicates the attacker must win a timing window between concurrent operations, which can make reliable exploitation more difficult. Successful exploitation yields code execution on the host running the DNS Server service, which is a high-value target because the role typically runs on Windows Server domain controllers. Any organization running Microsoft DNS Server is affected, with the highest risk on servers that expose DNS (TCP/UDP 53) to untrusted networks or the internet. There is no evidence of active exploitation: it is not in CISA KEV, no public proof-of-concept is known, and the 0.6% EPSS (44th percentile) suggests modest near-term exploitation probability.

What to do: Treat internet-facing DNS servers and domain controllers as top patching priorities and apply Microsoft's fix for CVE-2026-69782 as soon as it is available. Until patched, restrict inbound access to TCP/UDP port 53 to trusted resolvers and enumerate which servers have the DNS Server role enabled (e.g., via 'Get-WindowsFeature DNS' on Windows Server). Note the high attack complexity means exploitation is timing-dependent, but do not deprioritize patching given unauthenticated network-triggered RCE on critical infrastructure hosts.