Description
Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Shell allows an authorized attacker to elevate privileges locally.
Published: 2026-04-14
Score: 7.8 High
EPSS: < 1% Very Low
KEV: No
Impact: Local Privilege Escalation
Action: Immediate Patch
AI Analysis

Impact

A race condition in the Windows Shell allows an authorized user to perform concurrent operations on a shared resource without proper synchronization. Exploiting this flaw can elevate the user’s privileges locally, granting higher access levels within the same system.

Affected Systems

The vulnerability affects Microsoft Windows 10 versions 1809, 21H2, and 22H2; Windows 11 releases 22H3, 23H2, 24H2, 25H2, and 26H1; and Windows Server 2019, Windows Server 2019 Server Core, Windows Server 2022, the Windows Server 2022 23H2 Edition Server Core, Windows Server 2025, and Windows Server 2025 Server Core installations.

Risk and Exploitability

Assigned a CVSS v3.1 score of 7.8, the flaw carries a high severity rating. EPSS data is not available, and the vulnerability is not listed in the CISA KEV catalog. The most probable attack vector is a local, authenticated attacker who can repeatedly invoke the Windows Shell to trigger the race condition. Given the high impact and lack of public exploitation evidence, systems should apply remediation promptly.

Generated by OpenCVE AI on April 14, 2026 at 20:09 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Download the security update for CVE-2026-27918 from the Microsoft Security Update Guide
  • Install the update on all affected Windows and Windows Server installations
  • Restart the systems to complete the application of the patch
  • Verify the patch has been applied by checking Windows Update history or a Security Baseline report

Generated by OpenCVE AI on April 14, 2026 at 20:09 UTC.

Tracking

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Advisories

No advisories yet.

History

Wed, 15 Apr 2026 21:15:00 +0000

Type Values Removed Values Added
First Time appeared Microsoft windows 10 21h2
Microsoft windows 10 22h2
Microsoft windows 11 22h3
Microsoft windows 11 23h2
Microsoft windows 11 24h2
Microsoft windows 11 25h2
Microsoft windows 11 26h1
Microsoft windows Server 2019 (server Core Installation)
Microsoft windows Server 2022, 23h2 Edition (server Core Installation)
Microsoft windows Server 2025 (server Core Installation)
Vendors & Products Microsoft windows 10 21h2
Microsoft windows 10 22h2
Microsoft windows 11 22h3
Microsoft windows 11 23h2
Microsoft windows 11 24h2
Microsoft windows 11 25h2
Microsoft windows 11 26h1
Microsoft windows Server 2019 (server Core Installation)
Microsoft windows Server 2022, 23h2 Edition (server Core Installation)
Microsoft windows Server 2025 (server Core Installation)

Tue, 14 Apr 2026 19:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Tue, 14 Apr 2026 17:30:00 +0000

Type Values Removed Values Added
Description Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Shell allows an authorized attacker to elevate privileges locally.
Title Windows Shell Elevation of Privilege Vulnerability
First Time appeared Microsoft
Microsoft windows 10 1809
Microsoft windows 10 21h2
Microsoft windows 10 22h2
Microsoft windows 11 23h2
Microsoft windows 11 24h2
Microsoft windows 11 25h2
Microsoft windows 11 26h1
Microsoft windows Server 2019
Microsoft windows Server 2022
Microsoft windows Server 2025
Microsoft windows Server 23h2
Weaknesses CWE-362
CPEs cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x86:*
cpe:2.3:o:microsoft:windows_10_21H2:*:*:*:*:*:*:x86:*
cpe:2.3:o:microsoft:windows_10_22H2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_11_23H2:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_11_23H2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_11_24H2:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_11_25H2:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_11_26H1:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_23h2:*:*:*:*:*:*:*:*
Vendors & Products Microsoft
Microsoft windows 10 1809
Microsoft windows 10 21h2
Microsoft windows 10 22h2
Microsoft windows 11 23h2
Microsoft windows 11 24h2
Microsoft windows 11 25h2
Microsoft windows 11 26h1
Microsoft windows Server 2019
Microsoft windows Server 2022
Microsoft windows Server 2025
Microsoft windows Server 23h2
References
Metrics cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C'}

Subscriptions

Microsoft Windows 10 1809 Windows 10 21h2 Windows 10 21h2 Windows 10 22h2 Windows 10 22h2 Windows 11 22h3 Windows 11 23h2 Windows 11 23h2 Windows 11 24h2 Windows 11 24h2 Windows 11 25h2 Windows 11 25h2 Windows 11 26h1 Windows 11 26h1 Windows Server 2019 Windows Server 2019 (server Core Installation) Windows Server 2022 Windows Server 2022, 23h2 Edition (server Core Installation) Windows Server 2025 Windows Server 2025 (server Core Installation) Windows Server 23h2
cve-icon MITRE

Status: PUBLISHED

Assigner: microsoft

Published:

Updated: 2026-04-20T20:24:33.205Z

Reserved: 2026-02-24T21:35:49.687Z

Link: CVE-2026-27918

cve-icon Vulnrichment

Updated: 2026-04-14T18:05:09.843Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-04-14T18:17:00.720

Modified: 2026-04-17T15:10:35.607

Link: CVE-2026-27918

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-04-15T21:00:09Z

Weaknesses