VulnerabilityAnalyzed

CVE-2026-21519

Microsoft Windows Type Confusion Vulnerability

KEVHIGH 7.8EPSS 2.46%

Does this matter?

Known to be exploited in the wild (CISA KEV, CISA remediation deadline 3 March 2026). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.

Description

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

CVSS 3.1: 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS: 2.46% probability · 84th percentile
CISA KEV: Listed 10 February 2026 · due 3 March 2026
Weakness: CWE-843
Affected: microsoft/windows 10 1607 · 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 server 2016 · microsoft/windows server 2019 · microsoft/windows server 2022 · microsoft/windows server 2022 23h2 · microsoft/windows server 2025
Source: secure@microsoft.com

CISA notes

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21519 ; https://nvd.nist.gov/vuln/detail/CVE-2026-21519

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21519Vendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-21519US Government Resource

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.