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TI-2021-18721 Aliases CVE-2021-42286GHSA-gpw2-42fw-wq8h

Windows Core Shell SI Host Extension Framework for Composable Shell Elevation of Privilege Vulnerability

Priority LOW 37CWE-269Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Privilege escalation
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 Core Shell SI Host Extension Framework for Composable Shell Elevation of Privilege Vulnerability

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0049 42nd percentileScored 2026-11-07
Fix Fixed Microsoft: 1 update

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
MicrosoftWindows 10 Version 200410.0.0 to before 10.0.19041.134810.0.19041.1348Patch availableCNA
MicrosoftWindows 10 Version 20H210.0.0 to before 10.0.19042.134810.0.19042.1348Patch availableCNA
MicrosoftWindows 10 Version 21H110.0.0 to before 10.0.19043.134810.0.19043.1348Patch availableCNA
MicrosoftWindows Server version 200410.0.0 to before 10.0.19041.134810.0.19041.1348Patch availableCNA
MicrosoftWindows Server version 20H210.0.0 to before 10.0.19041.134810.0.19041.1348Patch availableCNA
  • Windows 10 Version 2004 VendorMicrosoft Affected 10.0.0 to before 10.0.19041.1348 Fixed in 10.0.19041.1348 Patch available CNA
  • Windows 10 Version 20H2 VendorMicrosoft Affected 10.0.0 to before 10.0.19042.1348 Fixed in 10.0.19042.1348 Patch available CNA
  • Windows 10 Version 21H1 VendorMicrosoft Affected 10.0.0 to before 10.0.19043.1348 Fixed in 10.0.19043.1348 Patch available CNA
  • Windows Server version 2004 VendorMicrosoft Affected 10.0.0 to before 10.0.19041.1348 Fixed in 10.0.19041.1348 Patch available CNA
  • Windows Server version 20H2 VendorMicrosoft Affected 10.0.0 to before 10.0.19041.1348 Fixed in 10.0.19041.1348 Patch available CNA

CPE configurations NVD · 11

CPEVersionsRoleVendor
cpe:2.3:o:microsoft:windows_10:20h2:*:*:*:*:*:arm64:*20h2VulnerableMicrosoft
cpe:2.3:o:microsoft:windows_10:20h2:*:*:*:*:*:x64:*20h2VulnerableMicrosoft
cpe:2.3:o:microsoft:windows_10:20h2:*:*:*:*:*:x86:*20h2VulnerableMicrosoft
cpe:2.3:o:microsoft:windows_10:21h1:*:*:*:*:*:arm64:*21h1VulnerableMicrosoft
cpe:2.3:o:microsoft:windows_10:21h1:*:*:*:*:*:x64:*21h1VulnerableMicrosoft
cpe:2.3:o:microsoft:windows_10:21h1:*:*:*:*:*:x86:*21h1VulnerableMicrosoft
cpe:2.3:o:microsoft:windows_10:2004:*:*:*:*:*:arm64:*2004VulnerableMicrosoft
cpe:2.3:o:microsoft:windows_10:2004:*:*:*:*:*:x64:*2004VulnerableMicrosoft
cpe:2.3:o:microsoft:windows_10:2004:*:*:*:*:*:x86:*2004VulnerableMicrosoft
cpe:2.3:o:microsoft:windows_server:20h2:*:*:*:*:*:*:*20h2VulnerableMicrosoft
  • cpe:2.3:o:microsoft:windows_10:20h2:*:*:*:*:*:arm64:* Versions 20h2 Vulnerable ·Microsoft
  • cpe:2.3:o:microsoft:windows_10:20h2:*:*:*:*:*:x64:* Versions 20h2 Vulnerable ·Microsoft
  • cpe:2.3:o:microsoft:windows_10:20h2:*:*:*:*:*:x86:* Versions 20h2 Vulnerable ·Microsoft
  • cpe:2.3:o:microsoft:windows_10:21h1:*:*:*:*:*:arm64:* Versions 21h1 Vulnerable ·Microsoft
  • cpe:2.3:o:microsoft:windows_10:21h1:*:*:*:*:*:x64:* Versions 21h1 Vulnerable ·Microsoft
  • cpe:2.3:o:microsoft:windows_10:21h1:*:*:*:*:*:x86:* Versions 21h1 Vulnerable ·Microsoft
  • cpe:2.3:o:microsoft:windows_10:2004:*:*:*:*:*:arm64:* Versions 2004 Vulnerable ·Microsoft
  • cpe:2.3:o:microsoft:windows_10:2004:*:*:*:*:*:x64:* Versions 2004 Vulnerable ·Microsoft
  • cpe:2.3:o:microsoft:windows_10:2004:*:*:*:*:*:x86:* Versions 2004 Vulnerable ·Microsoft
  • cpe:2.3:o:microsoft:windows_server:20h2:*:*:*:*:*:*:* Versions 20h2 Vulnerable ·Microsoft
Show 1 more CPE
CPEVersionsRoleVendor
cpe:2.3:o:microsoft:windows_server_2016:2004:*:*:*:*:*:*:*2004VulnerableMicrosoft
  • cpe:2.3:o:microsoft:windows_server_2016:2004:*:*:*:*:*:*:* Versions 2004 Vulnerable ·Microsoft

Remediation

Microsoft 1 update

  • KB5007186
    Security Update
    • Microsoft Edge (Chromium-based) in IE Mode 10.0.19041.1348, 10.0.19043.1348, 10.0.19042.1348
    • Windows 10 Version 2004 for 32-bit Systems 10.0.19041.1348
    • Windows 10 Version 2004 for ARM64-based Systems 10.0.19041.1348
    • Windows 10 Version 2004 for x64-based Systems 10.0.19041.1348
    • Windows 10 Version 20H2 for 32-bit Systems 10.0.19042.1348
    • Windows 10 Version 20H2 for ARM64-based Systems 10.0.19042.1348
    • Windows 10 Version 21H1 for 32-bit Systems 10.0.19043.1348
    • Windows 10 Version 21H1 for ARM64-based Systems 10.0.19043.1348
    • Windows 10 Version 21H1 for x64-based Systems 10.0.19043.1348
    • Windows Server, version 2004 (Server Core installation) 10.0.19041.1348
    • Windows Server, version 20H2 (Server Core Installation) 10.0.19041.1348, 10.0.19042.1348

Vendor assessments

Microsoft

Microsoft's page for this CVE →

Impact
Elevation of Privilege
Exploited
No
Publicly disclosed
No
Exploitability
Exploitation Less Likely

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-42286
  2. 2026-10-03 Alias added: GHSA-gpw2-42fw-wq8h

References

Patch 2

  • 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
See all 2973 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences