CVE-2021-26417

Local disclosure of sensitive data

Published Apr 13, 2021 · Updated Nov 19, 2024

Information disclosure in the Windows Overlay Filter in affected Microsoft Windows 10 and Windows Server releases allows local users to read sensitive data. Microsoft has not published the flawed operation, input path, or data exposed by the overlay-filter implementation. Exploitation requires low-privileged code execution on the target and needs no user interaction; the published impact is limited to confidentiality.

CVSS severity5.5
Medium
EPSS probability0.81%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in the Windows Overlay Filter in affected Microsoft Windows 10 and Windows Server releases allows local users to read sensitive data. Microsoft has not published the flawed operation, input path, or data exposed by the overlay-filter implementation. Exploitation requires low-privileged code execution on the target and needs no user interaction; the published impact is limited to confidentiality.

The record

CVE
CVE-2021-26417
Published
Apr 13, 2021
Updated
Nov 19, 2024
Vendor
Microsoft
Product
Windows Server 2019
Classifications
Unavailable
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 13, 2021CVE publishedPublication date reported by the CVE source.
  2. Nov 19, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=10.0.0 <publication

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Microsoft · Windows Server 2019version=10.0.0 <publication
Microsoft · Windows 10 Version 1909version=10.0.0 <publication
Microsoft · Windows Server, version 2004version=10.0.0 <publication
Microsoft · Windows 10 Version 20H2version=10.0.0 <publication
Microsoft · Windows Server 2019 (Server Core installation)version=10.0.0 <publication
Microsoft · Windows Server version 20H2version=10.0.0 <publication
Microsoft · Windows 10 Version 2004version=10.0.0 <publication
Microsoft · Windows 10 Version 1809version=10.0.0 <publication
Microsoft · Windows Server, version 1909 (Server Core installation)version=10.0.0 <publication

Published CVSS scores

5.5MicrosoftCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
2.1NVDAV:L/AC:L/Au:N/C:P/I:N/A:N
5.5NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 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

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Your stack

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