HIGHCVSS 7.8Actively exploited · CISA KEV since 2021-11-03Vulnerability

CVE-2021-33771

Microsoft Windows kernel contains an unspecified vulnerability that allows for privilege escalation.

Properties

Euvd product
Windows Server 2016, Windows 10 Version 20H2, Windows 10 Version 1607, Windows 10 Version 21H1, Windows Server 2019, Windows 10 Version 1507, Windows Server version 20H2, Windows 10 Version 1909, Windows Server 2012 R2, Windows 10 Version 2004, Windows Server 2019 (Server Core installation), Windows Server 2012 R2 (Server Core installation), Windows 8.1, Windows Server 2016 (Server Core installation), Windows Server version 2004, Windows 10 Version 1809
Vulnerability name
Microsoft Windows Kernel Privilege Escalation Vulnerability
First seen
2026-08-10T15:11:03+00:00
Cvss score
7.8
Epss score
0.10172
Last seen
2026-10-19T12:00:27+00:00
Due date
2021-11-17
Euvd assigner
microsoft
Retrieved at
2026-10-21T01:24:47+00:00
Exploited euvd since
2021-11-03T00:00:00+00:00
Src batch id
epss_history-20261020T103617Z-728ddd
Source url
https://epss.empiricalsecurity.com/epss_scores-2026-10-19.csv.gz
Date added
2021-11-03
Euvd base score version
3.1
Score
7.8
Fetched at
2026-10-20T10:36:20+00:00
Euvd vendor
Microsoft
Cvss vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
In Signal since
initial import (Sep 2026)
Euvd base score
7.8

Related Entities (17)

AFFECTS_PRODUCT (14)

→[Product]cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*
→[Product]cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*
→[Product]cpe:2.3:o:microsoft:windows_server_20h2:*:*:*:*:*:*:*:*
→[Product]cpe:2.3:o:microsoft:windows_10_20h2:*:*:*:*:*:*:*:*
→[Product]cpe:2.3:o:microsoft:windows_10_2004:*:*:*:*:*:*:*:*
→[Product]cpe:2.3:o:microsoft:windows_server_2004:*:*:*:*:*:*:*:*
→[Product]cpe:2.3:o:microsoft:windows_8.1:-:*:*:*:*:*:*:*
→[Product]cpe:2.3:o:microsoft:windows_rt_8.1:-:*:*:*:*:*:*:*
→[Product]cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:*:*
→[Product]cpe:2.3:o:microsoft:windows_server_2012:-:r2:*:*:*:*:*:*
→[Product]cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:*:*
→[Product]cpe:2.3:o:microsoft:windows_10_1507:*:*:*:*:*:*:*:*
→[Product]cpe:2.3:o:microsoft:windows_10_21h1:*:*:*:*:*:*:*:*
→[Product]cpe:2.3:o:microsoft:windows_10_1909:*:*:*:*:*:*:*:*

DESCRIBES (1)

←[KEVEntry]Microsoft Windows Kernel Privilege Escalation Vulnerability

INVOLVES (1)

←[Signal]kev_added · 2021-11-03

MENTIONED_IN (1)

→[Campaign]Exposing AdFection: How Discover-Tech Turned Targeted Ads Into a Pipeline for Zero-Click Mercenary Spyware

Explore deeper with Ninja Signal's threat intelligence graph

Search in SpektrOpen Signal Desktop
CVE-2021-33771 (CVSS 7.8) — Ninja Signal Threat Intelligence | Ninja Signal