CVE-2026-21241: CWE-416: Use After Free in Microsoft Windows 11 version 22H3
Use after free in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.
AI Analysis
Technical Summary
This vulnerability (CVE-2026-21241) involves a use-after-free condition in the Windows Ancillary Function Driver for WinSock on Windows 11 version 22H3 (build 10.0.22631.0). Exploitation requires local access with some privileges and could allow an attacker to elevate their privileges on the affected system. The vulnerability is classified under CWE-416 (Use After Free). Microsoft has released an official patch to remediate this issue.
Potential Impact
Successful exploitation of this vulnerability could allow an authorized local attacker to elevate their privileges, potentially gaining higher-level access on the affected Windows 11 system. This could lead to full system compromise depending on the privileges gained.
Mitigation Recommendations
An official fix is available from Microsoft. Users and administrators should apply the security update provided in the Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21241 to remediate this vulnerability.
CVE-2026-21241: CWE-416: Use After Free in Microsoft Windows 11 version 22H3
Description
Use after free in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CVE-2026-21241) involves a use-after-free condition in the Windows Ancillary Function Driver for WinSock on Windows 11 version 22H3 (build 10.0.22631.0). Exploitation requires local access with some privileges and could allow an attacker to elevate their privileges on the affected system. The vulnerability is classified under CWE-416 (Use After Free). Microsoft has released an official patch to remediate this issue.
Potential Impact
Successful exploitation of this vulnerability could allow an authorized local attacker to elevate their privileges, potentially gaining higher-level access on the affected Windows 11 system. This could lead to full system compromise depending on the privileges gained.
Mitigation Recommendations
An official fix is available from Microsoft. Users and administrators should apply the security update provided in the Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21241 to remediate this vulnerability.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2025-12-11T21:02:05.735Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- official-fix
- Vendor Advisory Urls
- [{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21241","vendor":"Microsoft"}]
Threat ID: 698b75ff4b57a58fa1209fed
Added to database: 2/10/2026, 6:16:31 PM
Last enriched: 5/12/2026, 5:11:27 AM
Last updated: 5/22/2026, 10:15:21 AM
Views: 201
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