Reference page — cumulative record through Sunday, October 4, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2021-31956

CVE-2021-31956HIGH

Microsoft Windows 10 Version 1809 — Windows NTFS Elevation of Privilege Vulnerability

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   L   L   L   N  U  H  H  H    7.8   .2227   97.6   YES

AFFECTED
  Product                                         Versions  Fixed
  Windows 10 Version 1809                         10.0.0 –  —
  Windows Server 2019                             10.0.0 –  —
  Windows Server 2019 (Server Core installation)  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 Server version 2004                     10.0.0 –  —
  Windows 10 Version 20H2                         10.0.0 –  —
  Windows Server version 20H2                     10.0.0 –  —
  Windows 10 Version 1507                         10.0.0 –  —
  + 15 more

TIMELINE
  Apr 30  Reserved by microsoft
  Jun 8   Published (CNA: microsoft)
  Nov 3   Added to CISA KEV, remediation due 2021-11-17

CWE-191 · CNA: microsoft · CVSS v3.1 · 2 references · KEV due November 17, 2021

Description

Windows NTFS Elevation of Privilege Vulnerability

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
April 30, 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 — 25 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 Server 2019 (Server Core installation)	—	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 Server version 2004	—	10.0.0	—
Microsoft	Windows 10 Version 20H2	—	10.0.0	—
Microsoft	Windows Server 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 Server 2016 (Server Core installation)	—	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 (Server Core installation)	—	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 2008 R2 Service Pack 1 (Server Core installation)	—	6.0.0	—
Microsoft	Windows Server 2012	—	6.2.0	—
Microsoft	Windows Server 2012 (Server Core installation)	—	6.2.0	—
Microsoft	Windows Server 2012 R2	—	6.3.0	—
Microsoft	Windows Server 2012 R2 (Server Core installation)	—	6.3.0	—

Weaknesses

CWE-191

References (2)

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31956 [x_refsource_MISC]
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-31956 [government-resource]

Authoritative record: CVE-2021-31956 at cve.org

Vendors: microsoft

Weaknesses: CWE-191

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2021-31956 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 Sunday, October 4, 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.