CVE-2021-33739
Microsoft Desktop Window Manager (DWM) Core Library Privilege Escalation Vulnerability
Published Jun 8, 2021 · corrected/updated Jun 16, 2026 · Microsoft Windows · evidence confidence very high
Microsoft Desktop Window Manager (DWM) Core Library contains an unspecified vulnerability that allows for privilege escalation.
Grounded briefings
Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.
Executive
CVE-2021-33739 is a high public vulnerability record for Microsoft Windows. CISA lists it as known exploited. Published remediation guidance: Apply updates per vendor instructions. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.
System administrator
Identify whether Microsoft Windows is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: microsoft/windows 10 1909; microsoft/windows 10 2004; microsoft/windows 10 20h2; microsoft/windows 10 21h1. Published remediation guidance: Apply updates per vendor instructions. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.
Security analyst
Signals on file: CVSS 8.4, EPSS 6.6%. CISA lists it as known exploited. Sources contributing to this record: cisa_kev, cve_org, epss, nvd. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.
Exploitation and remediation
Exploitation evidence
Confirmed in CISA KEV since Jun 8, 2021. Listed in CISA KEV and VulnCheck KEV.
Patch and remediation
Apply updates per vendor instructions. CISA due date Nov 17, 2021.
Safe detection guidance
Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.
Technology hubs
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Jun 8, 2021 · Catalog
Detected
Microsoft Desktop Window Manager (DWM) Core Library contains an unspecified vulnerability that allows for privilege escalation.
Nov 3, 2021 · CISA KEV
Known exploited
Apply updates per vendor instructions.
Nov 17, 2021 · CISA KEV
Remediation due
Apply updates per vendor instructions.
Jun 16, 2026 · Catalog
Updated
Microsoft Desktop Window Manager (DWM) Core Library contains an unspecified vulnerability that allows for privilege escalation.
Affected
- cpe microsoft/windows 10 1909version unspecified
- cpe microsoft/windows 10 2004version unspecified
- cpe microsoft/windows 10 20h2version unspecified
- cpe microsoft/windows 10 21h1version unspecified
- cpe microsoft/windows server 2004version unspecified
- cpe microsoft/windows server 20h2version unspecified
- vendor Microsoft Windowsversion unspecified
Sources
- CISA KEVConfirmed exploitationCVE-2021-33739
Microsoft Desktop Window Manager (DWM) Core Library contains an unspecified vulnerability that allows for privilege escalation.
cisa.gov - CVE.orgVulnerability recordCVE-2021-33739
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2021-33739
30-day exploitation probability 6.6%
first.org - NIST NVDVulnerability recordCVE-2021-33739
Microsoft DWM Core Library Elevation of Privilege Vulnerability
nvd.nist.gov - VulnCheck KEVConfirmed exploitationCVE-2021-33739
Microsoft Desktop Window Manager (DWM) Core Library contains an unspecified vulnerability that allows for privilege escalation.
vulncheck.com