Remote code execution via Hyper-V
Published Mar 11, 2021 · Updated Aug 19, 2026
Remote code execution in Microsoft Windows Hyper-V on affected releases allows remote authenticated users to execute code via crafted guest traffic. Microsoft has not publicly disclosed the precise vulnerable Hyper-V component or input-validation operation. Access requires a low-privilege remote position associated with Hyper-V use, and successful exploitation can compromise the host and connected virtual machines.
Summary
What happened
Remote code execution in Microsoft Windows Hyper-V on affected releases allows remote authenticated users to execute code via crafted guest traffic. Microsoft has not publicly disclosed the precise vulnerable Hyper-V component or input-validation operation. Access requires a low-privilege remote position associated with Hyper-V use, and successful exploitation can compromise the host and connected virtual machines.
The record
- CVE
- CVE-2021-26867
- Published
- Mar 11, 2021
- Updated
- Aug 19, 2026
- Vendor
- Microsoft
- Product
- Windows 10 Version 1909
- Classifications
- Unavailable
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Mar 11, 2021CVE publishedPublication date reported by the CVE source.
- Aug 19, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=10.0.0 <10.0.18363.1440
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
No sourced classifications are available.
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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