Reference page — cumulative record through Wednesday, October 7, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2021-33742

CVE-2021-33742HIGH

Microsoft Windows 10 Version 1809 — Windows MSHTML Platform Remote Code Execution Vulnerability

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   H   N   R  U  H  H  H    7.5   .5941   99.1   YES

AFFECTED
  Product                  Versions  Fixed
  Windows 10 Version 1809  10.0.0 –  —
  Windows Server 2019      10.0.0 –  —
  Windows 10 Version 1909  10.0.0 –  —
  Windows 10 Version 21H1  10.0.0 –  —
  Windows 10 Version 2004  10.0.0 –  —
  Windows 10 Version 20H2  10.0.0 –  —
  Windows 10 Version 1507  10.0.0 –  —
  Windows 10 Version 1607  10.0.0 –  —
  Windows Server 2016      10.0.0 –  —
  Windows 7                6.1.0 –   —
  + 7 more

TIMELINE
  May 28  Reserved by microsoft
  Jun 8   Published (CNA: microsoft)
  Nov 3   Added to CISA KEV, remediation due 2021-11-17

CWE-787 · CNA: microsoft · CVSS v3.1 · 2 references · KEV due November 17, 2021

Description

Windows MSHTML Platform Remote Code Execution Vulnerability

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
May 28, 2021	Reserved	Reserved by microsoft
June 8, 2021	Published	Published (CNA: microsoft)
November 3, 2021	KEV ADDED	Added to CISA KEV, remediation due 2021-11-17

Affected

Affected products and packages — 17 rows
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
Microsoft	Windows 10 Version 1809	—	10.0.0	—
Microsoft	Windows Server 2019	—	10.0.0	—
Microsoft	Windows 10 Version 1909	—	10.0.0	—
Microsoft	Windows 10 Version 21H1	—	10.0.0	—
Microsoft	Windows 10 Version 2004	—	10.0.0	—
Microsoft	Windows 10 Version 20H2	—	10.0.0	—
Microsoft	Windows 10 Version 1507	—	10.0.0	—
Microsoft	Windows 10 Version 1607	—	10.0.0	—
Microsoft	Windows Server 2016	—	10.0.0	—
Microsoft	Windows 7	—	6.1.0	—
Microsoft	Windows 7 Service Pack 1	—	6.1.0	—
Microsoft	Windows 8.1	—	6.3.0	—
Microsoft	Windows Server 2008 Service Pack 2	—	6.0.0	—
Microsoft	Windows Server 2008 Service Pack 2	—	6.0.0	—
Microsoft	Windows Server 2008 R2 Service Pack 1	—	6.1.0	—
Microsoft	Windows Server 2012	—	6.2.0	—
Microsoft	Windows Server 2012 R2	—	6.3.0	—

Weaknesses

CWE-787

References (2)

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-33742 [x_refsource_MISC]
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-33742 [government-resource]

Authoritative record: CVE-2021-33742 at cve.org

Vendors: microsoft

Weaknesses: CWE-787

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2021-33742 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, October 7, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.