Windows Hyper-V Remote Code Execution Vulnerability
Priority MEDIUM 48Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Microsoft. Impact type from Microsoft.
Summary
Windows Hyper-V Remote Code Execution Vulnerability
Why it matters now
EPSS 0.02866 86th percentileScored 2026-11-07
Fix Fixed Microsoft: 2 updates
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Microsoft | Windows 10 Version 1909 | 10.0.0 to before 10.0.18363.1440 | 10.0.18363.1440 | Patch available | CNA |
| Microsoft | Windows 10 Version 2004 | 10.0.0 to before 10.0.19043.867 | 10.0.19043.867 | Patch available | CNA |
| Microsoft | Windows Server version 2004 | 10.0.0 to before 10.0.19043.867 | 10.0.19043.867 | Patch available | CNA |
| Microsoft | Windows Server version 20H2 | 10.0.0 to before 10.0.19043.867 | 10.0.19043.867 | Patch available | CNA |
| Microsoft | Windows Server, version 1909 (Server Core installation) | 10.0.0 to before 10.0.18363.1440 | 10.0.18363.1440 | Patch available | CNA |
- Windows 10 Version 1909 VendorMicrosoft Affected 10.0.0 to before 10.0.18363.1440 Fixed in 10.0.18363.1440 Patch available CNA
- Windows 10 Version 2004 VendorMicrosoft Affected 10.0.0 to before 10.0.19043.867 Fixed in 10.0.19043.867 Patch available CNA
- Windows Server version 2004 VendorMicrosoft Affected 10.0.0 to before 10.0.19043.867 Fixed in 10.0.19043.867 Patch available CNA
- Windows Server version 20H2 VendorMicrosoft Affected 10.0.0 to before 10.0.19043.867 Fixed in 10.0.19043.867 Patch available CNA
- Windows Server, version 1909 (Server Core installation) VendorMicrosoft Affected 10.0.0 to before 10.0.18363.1440 Fixed in 10.0.18363.1440 Patch available CNA
CPE configurations NVD · 6
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:microsoft:windows_10:20h2:*:*:*:*:*:x64:* | 20h2 | Vulnerable | Microsoft |
| cpe:2.3:o:microsoft:windows_10:1909:*:*:*:*:*:x64:* | 1909 | Vulnerable | Microsoft |
| cpe:2.3:o:microsoft:windows_10:2004:*:*:*:*:*:x64:* | 2004 | Vulnerable | Microsoft |
| cpe:2.3:o:microsoft:windows_server_2016:20h2:*:*:*:*:*:*:* | 20h2 | Vulnerable | Microsoft |
| cpe:2.3:o:microsoft:windows_server_2016:1909:*:*:*:*:*:*:* | 1909 | Vulnerable | Microsoft |
| cpe:2.3:o:microsoft:windows_server_2016:2004:*:*:*:*:*:*:* | 2004 | Vulnerable | Microsoft |
- cpe:2.3:o:microsoft:windows_10:20h2:*:*:*:*:*:x64:* Versions 20h2 Vulnerable ·Microsoft
- cpe:2.3:o:microsoft:windows_10:1909:*:*:*:*:*:x64:* Versions 1909 Vulnerable ·Microsoft
- cpe:2.3:o:microsoft:windows_10:2004:*:*:*:*:*:x64:* Versions 2004 Vulnerable ·Microsoft
- cpe:2.3:o:microsoft:windows_server_2016:20h2:*:*:*:*:*:*:* Versions 20h2 Vulnerable ·Microsoft
- cpe:2.3:o:microsoft:windows_server_2016:1909:*:*:*:*:*:*:* Versions 1909 Vulnerable ·Microsoft
- cpe:2.3:o:microsoft:windows_server_2016:2004:*:*:*:*:*:*:* Versions 2004 Vulnerable ·Microsoft
Remediation
Microsoft 2 updates
- Security Update
- Internet Explorer 11 10.0.18363.1440
- Microsoft Edge (EdgeHTML-based) 10.0.18363.1440
- Windows 10 Version 1909 for 32-bit Systems 10.0.18363.1440
- Windows 10 Version 1909 for ARM64-based Systems 10.0.18363.1440
- Windows 10 Version 1909 for x64-based Systems 10.0.18363.1440
- Windows Server, version 1909 (Server Core installation) 10.0.18363.1440
- Security Update
- Internet Explorer 11 10.0.19043.867
- Microsoft Edge (EdgeHTML-based) 10.0.19043.867
- Windows 10 Version 2004 for 32-bit Systems 10.0.19043.867
- Windows 10 Version 2004 for ARM64-based Systems 10.0.19043.867
- Windows 10 Version 2004 for x64-based Systems 10.0.19043.867
- Windows 10 Version 20H2 for 32-bit Systems 10.0.19043.867
- Windows 10 Version 20H2 for ARM64-based Systems 10.0.19043.867
- Windows Server, version 2004 (Server Core installation) 10.0.19043.867
- Windows Server, version 20H2 (Server Core Installation) 10.0.19043.867
Vendor assessments
Microsoft
Microsoft's page for this CVE →
- Impact
- Remote Code Execution
- Exploited
- No
- Publicly disclosed
- No
- Exploitability
- Exploitation Less Likely
Timeline
- 2026-10-02 Threatist record created from CVE-2021-26867
- 2026-10-03 Alias added: GHSA-9wfr-5hw8-6f68
References
More Microsoft Windows 10 vulnerabilities
- TI-2015-02132 Buffer underflow in atmfd.dll in the Windows Adobe Type Manager Library in Microsoft… KEVCVSS 3.1HIGH 8.8
- TI-2022-10056 Remote Procedure Call Runtime Remote Code Execution Vulnerability CVSS 3.1CRITICAL 9.8
- TI-2022-06273 HTTP Protocol Stack Remote Code Execution Vulnerability CVSS 3.1CRITICAL 9.8
- TI-2019-00906 Remote Desktop Services Remote Code Execution Vulnerability CVSS 3.1CRITICAL 9.8
- TI-2022-15533 Windows Internet Key Exchange (IKE) Protocol Extensions Remote Code Execution Vulnerability CVSS 3.1CRITICAL 9.8
- TI-2015-01587 Mount Manager in Microsoft Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows… KEVCVSS 3.1MEDIUM 6.6
Sources
- CVE-2021-26867 · CVE Program
- CVE-2021-26867 · NVD
- FIRST EPSS
- GHSA-9wfr-5hw8-6f68 · GitHub Advisory Database · CC BY 4.0
- CVE-2021-26867 · Microsoft Security Update Guide
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences