CVE-2026-20838: CWE-209: Generation of Error Message Containing Sensitive Information in Microsoft Windows 11 version 23H2
Generation of error message containing sensitive information in Windows Kernel allows an authorized attacker to disclose information locally.
AI Analysis
Technical Summary
This vulnerability (CVE-2026-20838) involves the generation of error messages by the Windows Kernel in Windows 11 version 23H2 (build 10.0.22631.0) that contain sensitive information. An authorized attacker with local access can exploit this to disclose sensitive data. The issue is classified under CWE-209 (Generation of Error Message Containing Sensitive Information). Microsoft has published an official fix to remediate this vulnerability.
Potential Impact
An authorized local attacker can obtain sensitive information through error messages generated by the Windows Kernel. This could lead to information disclosure but does not affect system integrity or availability. The CVSS score of 5.5 reflects a medium impact primarily on confidentiality.
Mitigation Recommendations
An official fix is available from Microsoft. Users and administrators should apply the security update provided by Microsoft for Windows 11 version 23H2 to remediate this vulnerability. Refer to the Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20838 for the update details and installation instructions.
CVE-2026-20838: CWE-209: Generation of Error Message Containing Sensitive Information in Microsoft Windows 11 version 23H2
Description
Generation of error message containing sensitive information in Windows Kernel allows an authorized attacker to disclose information locally.
CVSS v3.1
Score 5.5medium
Affected software
Microsoft
Windows 11 version 23H2
Microsoft
Windows 11 Version 23H2
Microsoft
Windows 11 Version 24H2
Microsoft
Windows 11 Version 25H2
Microsoft
Windows Server 2022
Microsoft
Windows Server 2022, 23H2 Edition (Server Core installation)
Microsoft
Windows Server 2025
Microsoft
Windows Server 2025 (Server Core installation)
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CVE-2026-20838) involves the generation of error messages by the Windows Kernel in Windows 11 version 23H2 (build 10.0.22631.0) that contain sensitive information. An authorized attacker with local access can exploit this to disclose sensitive data. The issue is classified under CWE-209 (Generation of Error Message Containing Sensitive Information). Microsoft has published an official fix to remediate this vulnerability.
Potential Impact
An authorized local attacker can obtain sensitive information through error messages generated by the Windows Kernel. This could lead to information disclosure but does not affect system integrity or availability. The CVSS score of 5.5 reflects a medium impact primarily on confidentiality.
Mitigation Recommendations
An official fix is available from Microsoft. Users and administrators should apply the security update provided by Microsoft for Windows 11 version 23H2 to remediate this vulnerability. Refer to the Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20838 for the update details and installation instructions.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2025-12-03T05:54:20.376Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- official-fix
- Vendor Advisory Urls
- [{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20838","vendor":"Microsoft"}]
Threat ID: 69668adea60475309f9ae094
Added to database: 01/13/2026, 18:11:42 UTC
Last enriched: 07/30/2026, 23:46:54 UTC
Last updated: 09/10/2026, 22:26:02 UTC
Views: 244
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