CVE-2025-21333

Microsoft Windows Hyper-V NT Kernel Integration VSP contains a heap-based buffer overflow allowing local attackers to gain SYSTEM privileges.

This local privilege escalation vulnerability enables attackers to escalate to SYSTEM within the Hyper-V integration service, posing a severe risk to DIB environments relying on virtualization for secure workloads. While local access is required, the ability to gain SYSTEM privileges means a compromised VM can pivot to control the host or other VMs, complicating CMMC/NIST 800-171 compliance and requiring immediate patching and isolation of affected systems.

Shame score — A local privilege escalation vulnerability in a core Windows component that requires user interaction but grants SYSTEM access, representing a significant but avoidable risk if patching is delayed.