CVE-2026-21519MicrosoftOperating systemsFebruary 10, 2026

Microsoft Windows Type Confusion Vulnerability

High 7.8Actively exploited

Description

Microsoft Desktop Windows Manager contains a type confusion vulnerability that could allow an authorized attacker to elevate privileges locally.

What to do

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

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Details

Vendor
Microsoft
Product
Windows
CVE
CVE-2026-21519
Affected versions
Windows 10 Version 1607 10.0: from 10.0.14393.0 to 10.0.14393.8868 (excluded) — fixed in 10.0.14393.8868
Windows 10 Version 1809 10.0: from 10.0.17763.0 to 10.0.17763.8389 (excluded) — fixed in 10.0.17763.8389
Windows 10 Version 21H2 10.0: from 10.0.19044.0 to 10.0.19044.6937 (excluded) — fixed in 10.0.19044.6937
Windows 10 Version 22H2 10.0: from 10.0.19045.0 to 10.0.19045.6937 (excluded) — fixed in 10.0.19045.6937
Windows 11 version 22H3 10.0: from 10.0.22631.0 to 10.0.22631.6649 (excluded) — fixed in 10.0.22631.6649
Windows 11 Version 23H2 10.0: from 10.0.22631.0 to 10.0.22631.6649 (excluded) — fixed in 10.0.22631.6649
Windows 11 Version 24H2 10.0: from 10.0.26100.0 to 10.0.26100.7840 (excluded) — fixed in 10.0.26100.7840
Windows 11 Version 25H2 10.0: from 10.0.26200.0 to 10.0.26200.7840 (excluded) — fixed in 10.0.26200.7840
Windows 11 version 26H1 10.0: from 10.0.28000.0 to 10.0.28000.1575 (excluded) — fixed in 10.0.28000.1575
Windows 11 Version 26H1 10.0: from 10.0.28000.0 to 10.0.28000.1575 (excluded) — fixed in 10.0.28000.1575
Windows Server 2016 10.0: from 10.0.14393.0 to 10.0.14393.8868 (excluded) — fixed in 10.0.14393.8868
Windows Server 2016 (Server Core installation) 10.0: from 10.0.14393.0 to 10.0.14393.8868 (excluded) — fixed in 10.0.14393.8868
Windows Server 2019 10.0: from 10.0.17763.0 to 10.0.17763.8389 (excluded) — fixed in 10.0.17763.8389
Windows Server 2019 (Server Core installation) 10.0: from 10.0.17763.0 to 10.0.17763.8389 (excluded) — fixed in 10.0.17763.8389
Windows Server 2022 10.0: from 10.0.20348.0 to 10.0.20348.4773 (excluded) — fixed in 10.0.20348.4773
Windows Server 2022, 23H2 Edition (Server Core installation) 10.0: from 10.0.25398.0 to 10.0.25398.2149 (excluded) — fixed in 10.0.25398.2149
Windows Server 2025 10.0: from 10.0.26100.0 to 10.0.26100.32370 (excluded) — fixed in 10.0.26100.32370
Windows Server 2025 (Server Core installation) 10.0: from 10.0.26100.0 to 10.0.26100.32370 (excluded) — fixed in 10.0.26100.32370 (from the advisory and NVD; check the exact builds in the official advisory)
CVSS score
7.8
Actively exploited
Yes, listed in the CISA Known Exploited Vulnerabilities catalog
CISA due date
March 3, 2026 (deadline for US federal agencies: a good benchmark for you too)
Source
CISA KEV – original advisory
Published
February 10, 2026

The description and the recommended action are quoted from the public advisory; severity, exploitation status and affected versions are compiled automatically from public sources and may contain errors. The vendor's original advisory prevails: check it before taking action. This information is provided without warranty and does not replace a professional assessment.

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