CVE-2021-41336

Kernel information disclosure to low-privileged local users

Published Oct 13, 2021 · Updated Aug 4, 2024

Windows kernel information disclosure allows local users to read sensitive data on Windows 11 21H2 and Windows Server 2022. Microsoft has not disclosed the vulnerable kernel function, the input that reaches it, or the incorrect operation that exposes the data. A low-privileged local account is required; the reported consequence is confidentiality loss without data modification or service interruption.

CVSS severity5.5
Medium
EPSS probability0.73%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Windows kernel information disclosure allows local users to read sensitive data on Windows 11 21H2 and Windows Server 2022. Microsoft has not disclosed the vulnerable kernel function, the input that reaches it, or the incorrect operation that exposes the data. A low-privileged local account is required; the reported consequence is confidentiality loss without data modification or service interruption.

The record

CVE
CVE-2021-41336
Published
Oct 13, 2021
Updated
Aug 4, 2024
Vendor
Microsoft
Product
Windows 11 version 21H2
Classifications
Unavailable
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 13, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=10.0.0 <10.0.22000.258

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Microsoft · Windows 11 version 21H2version=10.0.0 <10.0.22000.258
Microsoft · Windows Server 2022version=10.0.0 <10.0.20348.288

Published CVSS scores

5.5Microsoft CorporationCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
2.1NIST NVDAV:L/AC:L/Au:N/C:P/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo