CVE-2021-42284
MediumCVSS 6.8Exploitation Probability (EPSS)
High risk88th percentile - higher than 88% of all known CVEs
Summary
A Denial of Service vulnerability in Windows Hyper-V. An attacker could exploit this to cause crashes or unavailability of virtualization services.
Risk Assessment
Risk of disruption of virtual machines and services dependent on Hyper-V, potentially leading to organizational downtime.
Recommendation
Install the Microsoft security update for Windows that addresses the DoS vulnerability in Hyper-V.
Other vulnerabilities in Windows Hyper-V
See all- CVE-2017-8714High
The Hyper-V component on Microsoft Windows 8.1, Windows Server 2012 Gold and R2, Windows 10 1607, and Windows Server 2016 has a vulnerability allowing remote code execution when it fails to properly validate input from an authenticated user on a guest operating system.
- CVE-2017-8664High
A vulnerability in Windows Hyper-V allows remote code execution when the system fails to properly validate input from a privileged user on a guest operating system.
- CVE-2017-0193High
A vulnerability in Windows Hyper-V allows an attacker to gain elevated privileges on a target guest operating system when Hyper-V instruction emulation fails to properly enforce privilege levels.
- CVE-2017-0212High
Windows Hyper-V contains a vulnerability that allows for elevation of privilege when Microsoft Windows 10 Gold, 1511, 1607, 1703, and Windows Server 2016 fail to properly validate vSMB packet data.
- CVE-2026-40402Critical
A use after free vulnerability in Windows Hyper-V allows an unauthorized attacker to elevate privileges locally.
- CVE-2021-26867Critical
Remote code execution vulnerability in Windows Hyper-V. An attacker could exploit this flaw to execute arbitrary code on the host.
- CVE-2026-61368Medium
Heap-based buffer overflow in Windows Hyper-V allows an authorized attacker to disclose information locally.
- CVE-2026-50680High
Heap-based buffer overflow in Windows Hyper-V allows an authorized attacker to elevate privileges locally.
- CVE-2026-50485Medium
In Windows Hyper-V, a buffer over-read vulnerability allows an authorized attacker to cause a denial of service (DoS) over an adjacent network.
- CVE-2026-54129High
A use-after-free vulnerability exists in Windows Hyper-V. This allows an authorized attacker to elevate privileges locally.
Original NVD description (English source)
Windows Hyper-V Denial of Service Vulnerability

