CVE-2020-1243
Windows Hyper-V Denial of Service Vulnerability
<p>A denial of service vulnerability exists when Microsoft Hyper-V on a host server fails to properly validate specific malicious data from a user on a guest operating system.</p> <p>To exploit the vulnerability, an attacker who already has a privileged account on a guest operating system, running as a virtual machine, could run a specially crafted application.</p> <p>The security update addresses the vulnerability by resolving the conditions where Hyper-V would fail to handle these requests.</p>
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Windows Hyper-V Denial of Service Vulnerability
<p>A denial of service vulnerability exists when Microsoft Hyper-V on a host server fails to properly validate specific malicious data from a user on a guest operating system.</p> <p>To exploit the vulnerability, an attacker who already has a privileged account on a guest operating system, running as a virtual machine, could run a specially crafted application.</p> <p>The security update addresses the vulnerability by resolving the conditions where Hyper-V would fail to handle these requests.</p>
- Record
CVE-2020-1243- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C - Updated
- 2026-11-02
EUVDEUVD-2020-12122
<p>A denial of service vulnerability exists when Microsoft Hyper-V on a host server fails to properly validate specific malicious data from a user on a guest operating system.</p> <p>To exploit the vulnerability, an attacker who already has a privileged account on a guest operating system, running as a virtual machine, could run a specially crafted application.</p> <p>The security update addresses the vulnerability by resolving the conditions where Hyper-V would fail to handle these requests.</p>
- Record
EUVD-2020-12122- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-xmww-w83v-qcv7
A denial of service vulnerability exists when Microsoft Hyper-V on a host server fails to...
A denial of service vulnerability exists when Microsoft Hyper-V on a host server fails to properly validate specific malicious data from a user on a guest operating system.To exploit the vulnerability, an attacker who already has a privileged account on a guest operating system, running as a virtual machine, could run a specially crafted application.The security update addresses the vulnerability by resolving the conditions where Hyper-V would fail to handle these requests., aka 'Windows Hyper-V Denial of Service Vulnerability'.
- Record
GHSA-xmww-w83v-qcv7- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
NVD
<p>A denial of service vulnerability exists when Microsoft Hyper-V on a host server fails to properly validate specific malicious data from a user on a guest operating system.</p> <p>To exploit the vulnerability, an attacker who already has a privileged account on a guest operating system, running as a virtual machine, could run a specially crafted application.</p> <p>The security update addresses the vulnerability by resolving the conditions where Hyper-V would fail to handle these requests.</p>
- Record
CVE-2020-1243- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 4.6 Medium
AV:L/AC:L/Au:N/C:P/I:P/A:P - Updated
- 2026-11-02
Affected products
- microsoft windows 10 version 1607
- microsoft windows 10 version 1709
- microsoft windows 10 version 1803
- microsoft windows 10 version 1809
- microsoft windows 10 version 1903 for x64-based systems
- microsoft windows 10 version 1909
- microsoft windows 10 version 2004
- microsoft windows server 2016
- microsoft windows server 2016 (server core installation)
- microsoft windows server 2019
- microsoft windows server 2019 (server core installation)
- microsoft windows server version 2004
History
| Recorded | Changed | Sources |
|---|---|---|
| facts | ||
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-1243 is a high vulnerability (CVSS 7.8) in Microsoft Windows 10 Version 1607, published October 16, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.90%, the 59th percentile. No source names a fixed version.