CVE-2026-20810: CWE-590: Free of Memory not on the Heap in Microsoft Windows 10 Version 1809
Free of memory not on the heap in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.
AI Analysis
Technical Summary
This vulnerability involves a use-after-free or improper free operation (CWE-590) in the Windows Ancillary Function Driver for WinSock on Windows 10 Version 1809 (build 10.0.17763.0). The flaw allows a local attacker with some level of authorization to elevate their privileges by triggering the improper memory free. The CVSS 3.1 base score is 7.8, reflecting high impact on confidentiality, integrity, and availability. Microsoft has published an official fix for this vulnerability.
Potential Impact
Successful exploitation allows an authorized local attacker to elevate privileges, potentially gaining higher system rights than intended. This can lead to full system compromise, including unauthorized access to sensitive data and disruption of system operations.
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-2026-20810 to remediate this vulnerability.
CVE-2026-20810: CWE-590: Free of Memory not on the Heap in Microsoft Windows 10 Version 1809
Description
Free of memory not on the heap in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.
CVSS v3.1
Score 7.8high
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability involves a use-after-free or improper free operation (CWE-590) in the Windows Ancillary Function Driver for WinSock on Windows 10 Version 1809 (build 10.0.17763.0). The flaw allows a local attacker with some level of authorization to elevate their privileges by triggering the improper memory free. The CVSS 3.1 base score is 7.8, reflecting high impact on confidentiality, integrity, and availability. Microsoft has published an official fix for this vulnerability.
Potential Impact
Successful exploitation allows an authorized local attacker to elevate privileges, potentially gaining higher system rights than intended. This can lead to full system compromise, including unauthorized access to sensitive data and disruption of system operations.
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-2026-20810 to remediate this vulnerability.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2025-12-03T05:54:20.372Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- official-fix
- Vendor Advisory Urls
- [{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20810","vendor":"Microsoft"}]
Threat ID: 69668adaa60475309f9adf4a
Added to database: 01/13/2026, 18:11:38 UTC
Last enriched: 07/30/2026, 23:56:10 UTC
Last updated: 09/10/2026, 19:36:52 UTC
Views: 158
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