CVE-2026-20816: 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 Installer allows an authorized attacker to elevate privileges locally.
AI Analysis
Technical Summary
This vulnerability involves a TOCTOU race condition in the Windows Installer component of Microsoft Windows 10 Version 1607 (build 10.0.14393.0). An authorized attacker with local access can exploit this timing issue to elevate their privileges on the affected system. The vulnerability is tracked as CVE-2026-20816 and is classified under CWE-367. Microsoft has published an official fix to remediate this issue.
Potential Impact
Successful exploitation of this vulnerability could allow an authorized local attacker to gain elevated privileges, potentially leading to full system compromise. The CVSS v3.1 base score of 7.8 reflects high impact on confidentiality, integrity, and availability. There are no known exploits in the wild at the time of this report.
Mitigation Recommendations
An official fix is available from Microsoft. Users and administrators should apply the security update provided by Microsoft for Windows 10 Version 1607 (build 10.0.14393.0) as soon as possible to mitigate this vulnerability. Refer to the Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20816 for detailed patch information and installation instructions.
CVE-2026-20816: 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 Installer 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 TOCTOU race condition in the Windows Installer component of Microsoft Windows 10 Version 1607 (build 10.0.14393.0). An authorized attacker with local access can exploit this timing issue to elevate their privileges on the affected system. The vulnerability is tracked as CVE-2026-20816 and is classified under CWE-367. Microsoft has published an official fix to remediate this issue.
Potential Impact
Successful exploitation of this vulnerability could allow an authorized local attacker to gain elevated privileges, potentially leading to full system compromise. The CVSS v3.1 base score of 7.8 reflects high impact on confidentiality, integrity, and availability. There are no known exploits in the wild at the time of this report.
Mitigation Recommendations
An official fix is available from Microsoft. Users and administrators should apply the security update provided by Microsoft for Windows 10 Version 1607 (build 10.0.14393.0) as soon as possible to mitigate this vulnerability. Refer to the Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20816 for detailed patch information and installation instructions.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2025-12-03T05:54:20.373Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- official-fix
- Vendor Advisory Urls
- [{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20816","vendor":"Microsoft"}]
Threat ID: 69668adba60475309f9adf8e
Added to database: 01/13/2026, 18:11:39 UTC
Last enriched: 07/30/2026, 23:49:44 UTC
Last updated: 09/10/2026, 19:36:52 UTC
Views: 284
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