CVE-2026-20831: CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition in Microsoft Windows 10 Version 1607
Time-of-check time-of-use (toctou) race condition in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.
AI Analysis
Technical Summary
This vulnerability is a TOCTOU race condition in the Windows Ancillary Function Driver for WinSock on Windows 10 Version 1607 (build 10.0.14393.0). It allows an authorized local attacker to elevate privileges by exploiting the timing window between checking a condition and using the resource. The vulnerability is tracked as CVE-2026-20831 with a CVSS 3.1 base score of 7.8 (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H). The issue is confirmed published and a patch is available from Microsoft.
Potential Impact
Successful exploitation allows an authorized local attacker to gain elevated privileges, potentially leading to full system compromise affecting confidentiality, integrity, and availability of the system. There are no known exploits in the wild at this time.
Mitigation Recommendations
A patch is available for this vulnerability. It is recommended to apply the official Microsoft update for Windows 10 Version 1607 (build 10.0.14393.0) to remediate this issue. No additional mitigation steps are specified.
CVE-2026-20831: CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition in Microsoft Windows 10 Version 1607
Description
Time-of-check time-of-use (toctou) race condition 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 is a TOCTOU race condition in the Windows Ancillary Function Driver for WinSock on Windows 10 Version 1607 (build 10.0.14393.0). It allows an authorized local attacker to elevate privileges by exploiting the timing window between checking a condition and using the resource. The vulnerability is tracked as CVE-2026-20831 with a CVSS 3.1 base score of 7.8 (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H). The issue is confirmed published and a patch is available from Microsoft.
Potential Impact
Successful exploitation allows an authorized local attacker to gain elevated privileges, potentially leading to full system compromise affecting confidentiality, integrity, and availability of the system. There are no known exploits in the wild at this time.
Mitigation Recommendations
A patch is available for this vulnerability. It is recommended to apply the official Microsoft update for Windows 10 Version 1607 (build 10.0.14393.0) to remediate this issue. No additional mitigation steps are specified.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2025-12-03T05:54:20.375Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 69668adda60475309f9adfea
Added to database: 1/13/2026, 6:11:41 PM
Last enriched: 4/3/2026, 12:43:33 PM
Last updated: 5/10/2026, 9:21:44 AM
Views: 97
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