High 7.8Known exploited (CISA KEV)Published Oct 12, 2021

CVE-2021-41357Win32k Elevation of Privilege Vulnerability

Updated under an hour ago (Oct 26, 2026, 1:50 PM ET)

Does this affect you?

It affects Microsoft Windows 10 Version 21H1 and 7 other products. Add what you run to find out whether that includes you.

CISA lists it as known exploited since Apr 25, 2022; federal agencies had to remediate by May 16, 2022. Treat that date as your deadline.

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Every CVE for Microsoft Windows 10 Version 21H1

Exploited in the last 30 days

Win32k Elevation of Privilege Vulnerability

CVSS: 7.8 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C
Weakness (CWE): Not given
Known exploited: Added to CISA KEV Apr 25, 2022; federal remediation due May 16, 2022Apply updates per vendor instructions.
EPSS (exploitation in the next 30 days): 1.58% (percentile 75)
Assigned by: microsoft
NVD analysis: Analyzed
Record last updated: Oct 21, 2025
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Microsoft Windows 10 Version 21H1 microsoft:windows_10_21h1	from 10.0.0 before 10.0.19043.1288	CNA record
Microsoft Windows Server 2022 microsoft:windows_server_2022	from 10.0.0 before 10.0.20348.288	CNA record
Microsoft Windows 10 Version 2004 microsoft:windows_10_1809	from 10.0.0 before 10.0.19041.1288	CNA record
Microsoft Windows Server version 2004 microsoft:windows_server_2004	from 10.0.0 before 10.0.19041.1288	CNA record
Microsoft Windows 10 Version 20H2 microsoft:windows_10_20h2	from 10.0.0 before 10.0.19042.1288	CNA record
Microsoft Windows Server version 20H2 microsoft:windows_server_20h2	from 10.0.0 before 10.0.19042.1288	CNA record
Microsoft Windows 11 version 21H2 microsoft:windows_11_21h2	from 10.0.0 before 10.0.22000.258	CNA record
microsoft windows_10_2004 microsoft:windows_10_2004	before 10.0.19041.1288	NVD
microsoft windows_10_20h2 microsoft:windows_10_20h2	before 10.0.19042.1288	NVD
microsoft windows_10_21h1 microsoft:windows_10_21h1	before 10.0.19043.1288	NVD
1–10 of 14

References

References

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-41357	x-refsource-misc, patch, vendor-advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-41357	us-government-resource

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.