CVE-2026-56177: CWE-416: Use After Free in Microsoft Windows 10 Version 1607
Description
CVE-2026-56177 is a use-after-free vulnerability in Microsoft Windows 10 Version 1607 and related builds that allows an authorized local attacker to elevate privileges. The flaw affects multiple Windows 10 builds prior to specific patch versions. Microsoft has released an official fix to address this high-severity vulnerability.
CVSS v3.1
Score 7.8high
Affected software
Microsoft
Windows 10 Version 1607
Microsoft
Windows 10 Version 1809
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 Server 2016
Microsoft
Windows Server 2016 (Server Core installation)
Microsoft
Windows Server 2019
Microsoft
Windows Server 2019 (Server Core installation)
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, identified as CWE-416 (Use After Free), exists in Windows Server components within Windows 10 Version 1607 and other related builds. It allows an authorized attacker with local access to exploit the use-after-free condition to elevate privileges on the affected system. The vulnerability has a CVSS 3.1 base score of 7.8, indicating high severity, with impacts including high confidentiality, integrity, and availability consequences. Multiple affected Windows 10 builds are specified, and Microsoft has issued an official fix to remediate the issue.
Potential Impact
An authorized local attacker can exploit this use-after-free vulnerability to gain elevated privileges, potentially allowing full control over the affected system. The vulnerability impacts confidentiality, integrity, and availability at a high level, enabling significant compromise of the system if exploited.
Mitigation Recommendations
Microsoft has released an official fix for this vulnerability. Users and administrators should apply the latest security updates from Microsoft for the affected Windows 10 versions to remediate this issue. No additional mitigation steps are specified beyond applying the official patch.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2026-06-19T13:53:31.989Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- official-fix
- Vendor Advisory Urls
- [{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-56177","vendor":"Microsoft"}]
Threat ID: 6aa044c4acd9273b49fa5fba
Added to database: 09/08/2026, 17:24:20 UTC
Last enriched: 10/16/2026, 20:48:16 UTC
Last updated: 10/23/2026, 15:10:13 UTC
Views: 28
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