CVE-2021-33739
HighExploitedPublic exploitMicrosoft DWM Core Library Elevation of Privilege Vulnerability
Published Jun 9, 2021 · Updated Oct 21, 2025
Key Facts
Patch immediately- CVE-2021-33739 is a high-severity vulnerability (CVSS 7.8 v3.1) affecting Windows 10 1809 (Microsoft), Windows 10 1909 (Microsoft), Windows 10 2004 (Microsoft) and 4 more products.
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Jun 8, 2021. Public exploit code is available.
- EPSS estimates a 6.6% probability of exploitation in the next 30 days.
- Fixed versions are available, including Windows 10 1809 10.0.18363.1621, Windows 10 1809 10.0.19041.1052, Windows 10 1909 10.0.18363.1621.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
7.8
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
6.6%
Higher than 93.7% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2021-33739 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
Description
Microsoft DWM Core Library Elevation of Privilege Vulnerability
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Nov 3, 2021 | Nov 17, 2021 | Not reported |
| Industry KEV feed | Jun 8, 2021 | Nov 17, 2021 | Not reported |
| CIRCL KEV | Nov 3, 2021 | Nov 17, 2021 | Not reported |
| ENISA EUVD | Nov 3, 2021 | n/a | Not reported |
Required action: Apply updates per vendor instructions.
Affected Products
17 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Windows 10 1809Microsoft | 10.0.18363.1621, 10.0.19041.1052 | 10.0.18363.1621 |
| Windows 10 1909Microsoft | 10.0.18363.1621 | 10.0.18363.1621 |
| Windows 10 2004Microsoft | See advisory | 10.0.19041.1052 |
| windows 10 20H2Microsoft | 10.0.19042.1052 | 10.0.19042.1052 |
| windows 10 21H1Microsoft | 10.0.19043.1052 | 10.0.19043.1052 |
Patched Releases
Windows 10 1809
10.0.18363.1621, 10.0.19041.1052
Windows 10 1909
10.0.18363.1621
Windows 10 2004
10.0.19041.1052
windows 10 20H2
10.0.19042.1052
windows 10 21H1
10.0.19043.1052
Windows Server 2004
10.0.19041.1052
windows server 20H2
10.0.19042.1052
Timeline
Added to Industry KEV feed
Jun 8, 2021
Publicly disclosed
Jun 9, 2021
Added to CISA KEV
Nov 3, 2021
Added to CIRCL KEV
Nov 3, 2021
Added to ENISA EUVD
Nov 3, 2021
Last updated
Oct 21, 2025
References
- advisoryhttps://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-26420
- advisoryhttps://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-31199
- advisoryhttps://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-31201
- advisoryhttps://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-31938
- advisoryhttps://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-31939
FAQ
Common Questions.
Microsoft DWM Core Library Elevation of Privilege Vulnerability
Affected: Windows 10 1809 (Microsoft) versions 10.0.18363.1621, 10.0.19041.1052; Windows 10 1909 (Microsoft) versions 10.0.18363.1621; Windows 10 2004 (Microsoft), among others. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Jun 8, 2021.
Yes. It was added on Nov 3, 2021 with a federal remediation due date of Nov 17, 2021.
Public exploit code is available.
Fixed versions are available, including Windows 10 1809 10.0.18363.1621, Windows 10 1809 10.0.19041.1052, Windows 10 1909 10.0.18363.1621.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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