CVE-2026-96858: CWE-306: Missing Authentication for Critical Function in Microsoft Windows 10 Version 21H2
Description
CVE-2026-96858 is a vulnerability in Microsoft Windows 10 Version 21H2 involving missing authentication for a critical function in the Windows Security Account Manager. This flaw allows an authorized local attacker to perform tampering actions without proper authentication. The vulnerability has a medium severity with a CVSS score of 5.5. Microsoft has released an official fix addressing this issue.
CVSS v3.1
Score 5.5medium
Affected software
Microsoft
Windows 10 Version 21H2
Microsoft
Windows 10 Version 22H2
Microsoft
Windows 11 version 23H2
Microsoft
Windows 11 Version 23H2
Microsoft
Windows 11 Version 24H2
Microsoft
Windows 11 Version 25H2
Microsoft
Windows 11 version 26H1
Microsoft
Windows 11 Version 26H2
Microsoft
Windows Server 2022
Microsoft
Windows Server 2025
Microsoft
Windows Server 2025 (Server Core installation)
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CVE-2026-96858) in Windows 10 Version 21H2 arises from missing authentication controls on a critical function within the Windows Security Account Manager. An authorized attacker with local access can exploit this to tamper with system components or configurations. The CVSS 3.1 base score is 5.5, reflecting a medium severity with low attack complexity and requiring privileges but no user interaction. Microsoft has published an official fix for affected versions.
Potential Impact
An authorized local attacker can tamper with critical functions in the Windows Security Account Manager due to missing authentication. This could lead to integrity violations but does not impact confidentiality or availability. The vulnerability requires local privileges and does not involve user interaction.
Mitigation Recommendations
Microsoft has released an official fix for this vulnerability. It is recommended to apply the security updates provided by Microsoft for the affected Windows 10 versions to remediate this issue.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2026-09-23T18:05:21.201Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- official-fix
- Vendor Advisory Urls
- [{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-96858","vendor":"Microsoft"}]
Threat ID: 6ace857d2cdf04f656a004ae
Added to database: 10/13/2026, 19:24:45 UTC
Last enriched: 10/14/2026, 00:04:22 UTC
Last updated: 10/14/2026, 00:04:22 UTC
Views: 2
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