Is CVE-2026-21519 actively exploited?

Yes. KEV Intelligence tracks CVE-2026-21519 as a known exploited vulnerability. Confidence is confirmed.

What exploitation activity has KEV Intelligence observed?

KEV Intelligence has not yet recorded sensor-observed exploitation attempts for CVE-2026-21519. Our sensors continue to monitor for activity targeting this CVE.

Which versions are affected?

CVE-2026-21519 affects Microsoft Windows 10 Version 1607 and 18 other products. KEV Intelligence lists 18 version rows; examples include 10.0.14393.0 to < 10.0.14393.8868, 10.0.17763.0 to < 10.0.17763.8389, and 10.0.19044.0 to < 10.0.19044.6937.

Yes. CVE-2026-21519 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. KEV Intelligence attested it 1 day ahead of CISA.

CVE-2026-21519 Exploited in the Wild — Windows 10 Version 1607, Windows 10 Version 1809, Windows 10 Version 21H2, Windows 10 Version 22H2, Windows 11 version 22H3, Windows 11 Version 23H2, Windows 11 Version 24H2, Windows 11 Version 25H2, Windows 11 version 26H1, Windows 11 Version 26H1, Windows Server 2016, Windows Server 2016 (Server Core installation), Windows Server 2019, Windows Server 2019 (Server Core installation), Windows Server 2022, Windows Server 2022, 23H2 Edition (Server Core installation), Windows Server 2025, Windows Server 2025 (Server Core installation)

Q: What is CVE-2026-21519?

CVE-2026-21519 is Desktop Window Manager Elevation of Privilege Vulnerability affecting Microsoft Windows 10 Version 1607 and 18 other products. Access of resource using incompatible type ('type confusion') in Desktop Window Manager allows an authorized attacker to elevate privileges locally.

Q: How should organizations remediate it?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Q: Is it in CISA KEV?

Yes. CVE-2026-21519 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. KEV Intelligence attested it 1 day ahead of CISA.

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2026-21519 is Desktop Window Manager Elevation of Privilege Vulnerability affecting Microsoft Windows 10 Version 1607 and 18 other products. Access of resource using incompatible type ('type confusion') in Desktop...

Is it exploited?

Yes. KEV Intelligence tracks this CVE as a known exploited vulnerability. Confidence is confirmed.

Who is affected?

Microsoft / Windows 10 Version 1607 affected before 10.0.14393.8868.

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

Desktop Window Manager Elevation of Privilege Vulnerability

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

Vendor Product Affected Status

Microsoft Windows 10 Version 1607 Before 10.0.14393.8868 Affected

Microsoft Windows 10 Version 1809 Before 10.0.17763.8389 Affected

Microsoft Windows 10 Version 21H2 Before 10.0.19044.6937 Affected

Microsoft Windows 10 Version 22H2 Before 10.0.19045.6937 Affected

Microsoft Windows 11 version 22H3 Before 10.0.22631.6649 Affected

Microsoft Windows 11 Version 23H2 Before 10.0.22631.6649 Affected

Microsoft Windows 11 Version 24H2 Before 10.0.26100.7840 Affected

Microsoft Windows 11 Version 25H2 Before 10.0.26200.7840 Affected

Microsoft Windows 11 version 26H1 Before 10.0.28000.1575 Affected

Microsoft Windows 11 Version 26H1 Before 10.0.28000.1575 Affected

Microsoft Windows Server 2016 Before 10.0.14393.8868 Affected

Microsoft Windows Server 2016 (Server Core installation) Before 10.0.14393.8868 Affected

Microsoft Windows Server 2019 Before 10.0.17763.8389 Affected

Microsoft Windows Server 2019 (Server Core installation) Before 10.0.17763.8389 Affected

Microsoft Windows Server 2022 Before 10.0.20348.4773 Affected

Microsoft Windows Server 2022, 23H2 Edition (Server Core installation) Before 10.0.25398.2149 Affected

Microsoft Windows Server 2025 Before 10.0.26100.32370 Affected

Microsoft Windows Server 2025 (Server Core installation) Before 10.0.26100.32370 Affected

View vendor advisory

Published: 10 Feb 2026
Exploitation Reported: 01 Jun 2026
Attack vector: Local
Complexity: Low
Privileges: Low
User interaction: None

CVE References

CVE Record CVE.org · CVE Record https://www.cve.org/CVERecord?id=CVE-2026-21519
Desktop Window Manager Elevation of Privilege Vulnerability msrc.microsoft.com · Vendor Advisory https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21519

Exploitation evidence

Why KEV Intelligence marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

CVE

Recorded 01 Jun 2026

Independent exploitation attestation added to the KEV Intelligence record.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the KEV Intelligence Pro API.

Learn about Pro API access

Source	Added
CVE First	2026-06-01 10:50 UTC
CISA	2026-06-02 14:03 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets: 0
User-Agents: 0

Raw values available in Pro and Enterprise.

Scanner coverage

No scanner integrations recorded yet.

Virtual patch status

No KEV Intelligence virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

No detection artifacts or sensor request patterns are available for this CVE yet.

Check back as sensor telemetry and scanner integrations are updated.

Risk and context

Severity, weaknesses, and research context

CVSS v3.1

7.8 High

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

EPSS

2.4%

Weaknesses

Access of Resource Using Incompatible Type ('Type Confusion') CWE-843

Timeline

From disclosure to observed exploitation

02 Jun 2026
Added to CISA KEV

Listed in the CISA Known Exploited Vulnerabilities catalog
01 Jun 2026
Added to KEV Intelligence KEV Feed

High-confidence, third-party attested exploitation
10 Feb 2026
CVE published

Vulnerability disclosed publicly
30 Dec 2025
CVE ID reserved

Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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Evidence confidence and provenance
First-party sensor telemetry
PoC and scanner references
Affected versions and enrichment
Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2026-21519

Free JSON includes basic KEV fields

{
  "cve_id": "CVE-2026-21519",
  "confidence": "Confirmed",
  "cvss_score": 7.8,
  "cvss_estimated": false,
  "epss_score": 0.0242,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}

CVE-2026-21519