CVE-2026-21519

HIGH7.8

CISA KEV

Published 2026-02-10 · Updated 2026-06-17 · Source secure@microsoft.com

Summary

CVE-2026-21519 is a high-severity (CVSS 7.8) vulnerability in Microsoft Windows. CISA added it to the Known Exploited Vulnerabilities catalog on February 10, 2026, which means exploitation in the wild has been confirmed; US federal agencies had to remediate it by March 3, 2026. CISA does not currently list it as used in ransomware campaigns. Microsoft has 390 vulnerabilities in the KEV catalog, 117 of them linked to ransomware.

All 390 known-exploited Microsoft vulnerabilities →

Description

Access of resource using incompatible type ('type confusion') in Desktop Window Manager allows an authorized attacker to elevate privileges locally.

CVSS vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CWE-843

CISA Known-Exploited Vulnerability

Product: Microsoft — Windows

Name: Microsoft Windows Type Confusion Vulnerability

Date added: 2026-02-10 · Due: 2026-03-03

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

References

View on NVD

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