CVE-2026-21237

highpriority · track · 0EPSS 0.003 · 20 %ileDEEUJPNLRUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

0.27% (20th) EPSS

CVSS 7 · high

Is it mine?

143 products

Check your exposure

Who says so?

7 sources

cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · scored 2026-10-27

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

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

FixedWindows 10 Version 21H2 for 32-bit Systemsmsrc_csaf
10.0.19044.6937:Security Update:https://support.microsoft.com/help/5075912
https://support.microsoft.com/help/5075912
FixedWindows 10 Version 21H2 for ARM64-based Systemsmsrc_csaf
10.0.19044.6937:Security Update:https://support.microsoft.com/help/5075912
https://support.microsoft.com/help/5075912
FixedWindows 10 Version 21H2 for x64-based Systemsmsrc_csaf
10.0.19044.6937:Security Update:https://support.microsoft.com/help/5075912
https://support.microsoft.com/help/5075912
FixedWindows 10 Version 22H2 for 32-bit Systemsmsrc_csaf
10.0.19045.6937:Security Update:https://support.microsoft.com/help/5075912
https://support.microsoft.com/help/5075912
FixedWindows 10 Version 22H2 for ARM64-based Systemsmsrc_csaf
10.0.19045.6937:Security Update:https://support.microsoft.com/help/5075912
https://support.microsoft.com/help/5075912
FixedWindows 10 Version 22H2 for x64-based Systemsmsrc_csaf
10.0.19045.6937:Security Update:https://support.microsoft.com/help/5075912
https://support.microsoft.com/help/5075912
FixedWindows 11 Version 23H2 for ARM64-based Systemsmsrc_csaf
10.0.22631.6649:Security Update:https://support.microsoft.com/help/5075941
https://support.microsoft.com/help/5075941
FixedWindows 11 Version 23H2 for x64-based Systemsmsrc_csaf
10.0.22631.6649:Security Update:https://support.microsoft.com/help/5075941
https://support.microsoft.com/help/5075941
FixedWindows 11 Version 24H2 for ARM64-based Systemsmsrc_csaf
10.0.26100.7840:Security Update:https://support.microsoft.com/help/5077181
https://support.microsoft.com/help/5077181
FixedWindows 11 Version 24H2 for x64-based Systemsmsrc_csaf
10.0.26100.7840:Security Update:https://support.microsoft.com/help/5077181
https://support.microsoft.com/help/5077181
FixedWindows 11 Version 25H2 for ARM64-based Systemsmsrc_csaf
10.0.26200.7840:Security Update:https://support.microsoft.com/help/5077181
https://support.microsoft.com/help/5077181
FixedWindows 11 Version 25H2 for x64-based Systemsmsrc_csaf
10.0.26200.7840:Security Update:https://support.microsoft.com/help/5077181
https://support.microsoft.com/help/5077181
FixedWindows 11 Version 26H1 for ARM64-based Systemsmsrc_csaf
10.0.28000.1575:Security Update:https://support.microsoft.com/help/5077179
https://support.microsoft.com/help/5077179
FixedWindows 11 version 26H1 for x64-based Systemsmsrc_csaf
10.0.28000.1575:Security Update:https://support.microsoft.com/help/5077179
https://support.microsoft.com/help/5077179
FixedWindows Server 2022msrc_csaf
10.0.20348.4773:Security Update:https://support.microsoft.com/help/5075906
https://support.microsoft.com/help/5075906
FixedWindows Server 2022 (Server Core installation)msrc_csaf
10.0.20348.4773:Security Update:https://support.microsoft.com/help/5075906
https://support.microsoft.com/help/5075906
FixedWindows Server 2022, 23H2 Edition (Server Core installation)msrc_csaf
10.0.25398.2149:Security Update:https://support.microsoft.com/help/5075897
https://support.microsoft.com/help/5075897
FixedWindows Server 2025msrc_csaf
10.0.26100.32370:Security Update:https://support.microsoft.com/help/5075899
https://support.microsoft.com/help/5075899
FixedWindows Server 2025 (Server Core installation)msrc_csaf
10.0.26100.32370:Security Update:https://support.microsoft.com/help/5075899
https://support.microsoft.com/help/5075899

cvss

Technical severity, 0–10. One row per scoring source.

7.0

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.4–7

v3.17highAV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU

v3.17highCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:Csecondary · ENISA EU

v3.17highCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:Hsecondary · secure@microsoft.com USexploitability 1 · impact 5.9

v3.16.4mediumCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)

v3.17highCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:Csecondary · NCSC-NL NL

v3.17highCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:Csecondary · Microsoft Security Response Center US

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: no · Technical Impact: totalcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-362USprimaryCWE-362USCWE-362USCWE-362USCWE-416USCWE-416US

affected products (143)

Products and version ranges known to be affected.

Hitachi Storageall versionscert_bundDEcpe:/h:hitachi:storage:-
Microsoft Exchange Server 2016 Cumulative Update 23all versionscert_bundDEcpe:/a:microsoft:exchange:server_2016_cumulative_update_23
Microsoft Exchange Server 2019 Cumulative Update 14all versionscert_bundDEcpe:/a:microsoft:exchange:server_2019_cumulative_update_14
Microsoft Exchange Server 2019 Cumulative Update 15all versionscert_bundDEcpe:/a:microsoft:exchange:server_2019_cumulative_update_15
Microsoft Windows 10 Version 1607all versionscert_bundDEcpe:/o:microsoft:windows_10:version_1607
Microsoft Windows 10 Version 1809all versionscert_bundDEcpe:/o:microsoft:windows_10:version_1809
Microsoft Windows 10 Version 21H2all versionscert_bundDEcpe:/o:microsoft:windows_10:version_21h2
Microsoft Windows 10 Version 22H2all versionscert_bundDEcpe:/o:microsoft:windows_10:version_22h2
Microsoft Windows 11 Version 23H2all versionscert_bundDEcpe:/o:microsoft:windows_11:version_23h2
Microsoft Windows 11 Version 24H2all versionscert_bundDEcpe:/o:microsoft:windows_11:version_24h2
Microsoft Windows 11 Version 25H2all versionscert_bundDEcpe:/o:microsoft:windows_11:version_25h2
Microsoft Windows 11 Version 26H1all versionscert_bundDEcpe:/o:microsoft:windows_11:version_26h1
Microsoft Windows 11 version 26H1all versionscert_bundDE
Microsoft Windows App for Macall versionscert_bundDEcpe:/o:microsoft:windows:app_for_mac
Microsoft Windows Server 2012all versionscert_bundDEcpe:/o:microsoft:windows_server_2012:-
Microsoft Windows Server 2012 R2all versionscert_bundDEcpe:/o:microsoft:windows_server_2012_r2:-
Microsoft Windows Server 2016all versionscert_bundDEcpe:/o:microsoft:windows_server_2016:-
Microsoft Windows Server 2019all versionscert_bundDEcpe:/o:microsoft:windows_server_2019:-
Microsoft Windows Server 2022all versionscert_bundDEcpe:/o:microsoft:windows_server_2022:-
Microsoft Windows Server 2022 23H2 Editionall versionscert_bundDEcpe:/o:microsoft:windows_server_2022:23h2_edition

showing 20 of 143

advisories (4)

Vendor and ecosystem advisories describing this.

NCSC-2026-0053Kwetsbaarheden verholpen in Microsoft WindowsNL2026-02-10csaf · ncsc_nlNL
Microsoft heeft kwetsbaarheden verholpen in Windows.
WID-SEC-W-2026-0369Microsoft Windows: Mehrere SchwachstellenDeutsch2026-02-10csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Microsoft Windows-Produkten ausnutzen, um Administratorrechte zu erlangen, beliebigen Code auszuführen, Sicherheitsmaßnahmen zu umgehen, Spoofing-Angriffe zu starten, Daten zu manipulieren, vertrauliche Informationen offenzulegen und einen Denial-of-Service-Zustand zu verursachen.
msrc_CVE-2026-21237Windows Subsystem for Linux Elevation of Privilege Vulnerability2026-02-10csaf · msrc_csafUS
To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle
JVNDB-2026-009406JVN iPedia advisory JVNDB-2026-0094062026-03-31vendor · jvndbJP

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu cert_bund ncsc_nl msrc_csaf jvndb NVD CVE.org MITRE

published 2026-02-10modified 2026-06-17

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+4134 more

references (3)

External citations — patches, advisories, analysis.

scry

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