๐Ÿ” CVE Alert

CVE-2026-21237

HIGH 7.0

Windows Subsystem for Linux Elevation of Privilege Vulnerability

CVSS Score
7.0
EPSS Score
0.0%
EPSS Percentile
9th

Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Subsystem for Linux allows an authorized attacker to elevate privileges locally.

Vendor microsoft
Product windows 10 version 21h2
Ecosystems
Industries
TechnologyEnterprise
Published Feb 10, 2026
Last Updated Apr 10, 2026
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CVSS v3 Breakdown

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability

Affected Versions

Microsoft / Windows 10 Version 21H2
10.0.19044.0 < 10.0.19044.6937
Microsoft / Windows 10 Version 22H2
10.0.19045.0 < 10.0.19045.6937
Microsoft / Windows 11 version 22H3
10.0.22631.0 < 10.0.22631.6649
Microsoft / Windows 11 Version 23H2
10.0.22631.0 < 10.0.22631.6649
Microsoft / Windows 11 Version 24H2
10.0.26100.0 < 10.0.26100.7840
Microsoft / Windows 11 Version 25H2
10.0.26200.0 < 10.0.26200.7840
Microsoft / Windows 11 version 26H1
10.0.28000.0 < 10.0.28000.1575
Microsoft / Windows 11 Version 26H1
10.0.28000.0 < 10.0.28000.1575
Microsoft / Windows Server 2022
10.0.20348.0 < 10.0.20348.4773
Microsoft / Windows Server 2022, 23H2 Edition (Server Core installation)
10.0.25398.0 < 10.0.25398.2149
Microsoft / Windows Server 2025
10.0.26100.0 < 10.0.26100.32370
Microsoft / Windows Server 2025 (Server Core installation)
10.0.26100.0 < 10.0.26100.32370

References

NVD โ†— CVE.org โ†— EPSS Data โ†—
msrc.microsoft.com: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21237