CVE-2020-1040VulnerabilityPublished 11/03/2021Updated 10/24/2026

CVE-2020-1040: Microsoft Hyper-V RemoteFX vGPU Remote Code Execution Vulnerability

Affects Microsoft Hyper-V RemoteFXSource CISA KEV

Severity

High

No CVSS score published yet

Exploitation: Actively exploited – in CISA KEV since 11/03/2021
KEV deadline: 05/03/2022
EPSS: 7.4% chance of exploitation in 30 days – higher than 94% of CVEs

What to do

CISA required action

Apply updates per vendor instructions.

nvd.nist.gov/vuln/detail/CVE-2020-1040 (opens in a new tab)

Description

CVE-2020-1040 is a high-severity vulnerability in Microsoft Hyper-V RemoteFX vGPU where improper input validation by the host server allows an authenticated user on a guest OS to execute remote code on the host OS. This vulnerability has been exploited in the wild.

Summary

Microsoft Hyper-V RemoteFX vGPU contains an improper input validation vulnerability because the host server does not properly validate input from an authenticated user on a guest operating system. Exploiting this flaw enables remote code execution on the host operating system, potentially allowing attackers to gain control over the host environment.

Impact

Successful exploitation allows remote code execution on the host operating system from an authenticated guest OS user, which can lead to full compromise of the host system. This vulnerability has been observed being exploited in the wild, indicating active threat usage.

Mitigation

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance.

Weaknesses

CWE-20Improper Input Validation (opens in a new tab)

What to do

Description

AnalysisAI-generated, updated 10/24/2026, 09:12:10 UTC

Weaknesses

References

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