dbcve.org
Actively exploited in the wild. This CVE is on the CISA Known Exploited Vulnerabilities list — treat remediation as urgent. Federal remediation due by 3 Mar 2026.
Windows 10 1607Operating system · Microsoft

CVE-2026-21519

HIGH · 7.8 CVSS v3.1 Published 2026-02-10
Fix available
A fix is available. Upgrade to 10.0.14393.8868 / 10.0.17763.8389 or later.
See remediation →
96/100
Remediation priority · Urgent
In the wild Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

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

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

A type confusion vulnerability in Windows Desktop Window Manager (dwm.exe) allows a local authenticated attacker to elevate privileges to SYSTEM level. The flaw occurs when the DWM processes window manager resources with incompatible type handling, enabling arbitrary code execution in an elevated context.

MitigationApply Microsoft security updates for CVE-2026-21519 when released. Prioritize patching domain controllers and systems with sensitive data. Verify that DWM service runs with appropriate least-privilege accounts and monitor for unusual DWM child process creation.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Windows 10 1607Operating system
Affected:< 10.0.14393.8868
Windows 10 1809Operating system
Affected:< 10.0.17763.8389
Windows 10 21h2Operating system
Affected:< 10.0.19044.6937
Windows 10 22h2Operating system
Affected:< 10.0.19045.6937
Windows 11 23h2Operating system
Affected:< 10.0.22631.6649
Windows 11 24h2Operating system
Affected:< 10.0.26100.7781
Windows 11 25h2Operating system
Affected:< 10.0.26200.7781
Windows Server 2016Operating system
Affected:< 10.0.14393.8868

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify the Windows build number
    Run `winver` from the command prompt or execute `systeminfo | findstr /B /C:"OS Name" /C:"OS Version"` to retrieve the full Windows version and build information.
    Affected if The build number falls below any of these thresholds: 14393.8868 (Win10 1607/Server 2016), 17763.8389 (Win10 1809), 19044.6937 (Win10 21h2), 19045.6937 (Win10 22h2), 22631.6649 (Win11 23h2), 26100.7781 (Win11 24h2), or 26200.7781 (Win11 25h2).
  2. Confirm dwm.exe is running
    Open Task Manager, go to the Details tab, and locate dwm.exe, or run `tasklist | findstr dwm.exe` from an elevated command prompt.
    Affected if dwm.exe is present and running (this is the default state on desktop Windows and Windows Server with Desktop Experience).
  3. Retrieve the dwm.exe file version directly
    Right-click on dwm.exe in `C:\Windows\System32\dwm.exe`, select Properties, and view the File version, or run `powershell -Command "(Get-Item 'C:\Windows\System32\dwm.exe').VersionInfo.FileVersion"`.
    Affected if The file version number is lower than the corresponding Windows build version thresholds listed in the affected products.

You are affected if your Windows build number is lower than the version thresholds AND dwm.exe is running on your system, allowing a locally authenticated attacker to escalate to SYSTEM privileges.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 10.0.14393.8868 / 10.0.17763.8389 / 10.0.19044.6937 or later
Fixed in 10.0.14393.886810.0.17763.838910.0.19044.6937
Interim mitigation

Apply Microsoft security updates for CVE-2026-21519 when released. Prioritize patching domain controllers and systems with sensitive data. Verify that DWM service runs with appropriate least-privilege accounts and monitor for unusual DWM child process creation.

Recommended fix High confidence

Windows 10 1607: 10.0.14393.8868 | Windows 10 1809: 10.0.17763.8389 | Windows 10 21h2: 10.0.19044.6937 | Windows 10 22h2: 10.0.19045.6937 | Windows 11 23h2: 10.0.22631.6649 | Windows 11 24h2: 10.0.26100.7781 | Windows 11 25h2: 10.0.26200.7781 | Windows Server 2016: 10.0.14393.8868

  1. Apply the relevant Microsoft security update for CVE-2026-21519 through Windows Update or Microsoft Update Catalog
  2. Restart the affected system to complete the patch installation
  3. Verify the Desktop Window Manager (dwm.exe) version matches the fixed build number for your Windows version
  4. Confirm the patch was applied by checking Windows Update history or running 'winver' to verify the build number

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Windows 10 1607 Exploited in the wild — priority engagement
  • Consultation4.0 h
  • Implementation2.0 h
  • Testing8.0 h
  • Review / QA4.0 h
18.0 hours of engineering $3,080
Get it fixed fast

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,928.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-21519 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-21519 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data