CVE-2020-16891

CVE-2020-16891 is a high-severity vulnerability in Microsoft Windows 10 with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

Description

<p>A remote code execution vulnerability exists when Windows Hyper-V on a host server fails to properly validate input from an authenticated user on a guest operating system. To exploit the vulnerability, an attacker could run a specially crafted application on a guest operating system that could cause the Hyper-V host operating system to execute arbitrary code.</p> <p>An attacker who successfully exploited the vulnerability could execute arbitrary code on the host operating system.</p> <p>The security update addresses the vulnerability by correcting how Hyper-V validates guest operating system user input.</p>

Frequently asked questions

What is CVE-2020-16891?
<p>A remote code execution vulnerability exists when Windows Hyper-V on a host server fails to properly validate input from an authenticated user on a guest operating system. To exploit the vulnerability, an attacker could run a specially crafted application on a guest operating system that could cause the Hyper-V host operating system to execute arbitrary code.</p> <p>An attacker who successfully exploited the vulnerability could execute arbitrary code on the host operating system.</p> <p>The security update addresses the vulnerability by correcting how Hyper-V validates guest operating system user input.</p>
How severe is CVE-2020-16891?
CVE-2020-16891 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-16891 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (56th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-16891?
CVE-2020-16891 primarily affects Microsoft Windows 10. In total, 19 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-16891?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2020-16891 published?
CVE-2020-16891 was published on 2020-10-16 and last updated on 2026-06-17.

References

Affected products (19)

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