CVE-2026-40403: CWE-122: Heap-based Buffer Overflow in Microsoft Windows 10 Version 1607
Heap-based buffer overflow in Windows Win32K - GRFX allows an authorized attacker to execute code locally.
AI Analysis
Technical Summary
This vulnerability (CVE-2026-40403) involves a heap-based buffer overflow in the Windows Win32K GRFX subsystem on Windows 10 Version 1607 (build 10.0.14393.0). An attacker with local privileges can exploit this flaw to execute arbitrary code, potentially leading to full system compromise. Microsoft has published an official fix to address this issue.
Potential Impact
Successful exploitation allows an authorized local attacker to execute arbitrary code with high impact on confidentiality, integrity, and availability. This can lead to complete system compromise on affected Windows 10 Version 1607 systems.
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-2026-40403 to remediate this vulnerability.
CVE-2026-40403: CWE-122: Heap-based Buffer Overflow in Microsoft Windows 10 Version 1607
Description
Heap-based buffer overflow in Windows Win32K - GRFX allows an authorized attacker to execute code locally.
CVSS v3.1
Score 8.8high
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CVE-2026-40403) involves a heap-based buffer overflow in the Windows Win32K GRFX subsystem on Windows 10 Version 1607 (build 10.0.14393.0). An attacker with local privileges can exploit this flaw to execute arbitrary code, potentially leading to full system compromise. Microsoft has published an official fix to address this issue.
Potential Impact
Successful exploitation allows an authorized local attacker to execute arbitrary code with high impact on confidentiality, integrity, and availability. This can lead to complete system compromise on affected Windows 10 Version 1607 systems.
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-2026-40403 to remediate this vulnerability.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2026-04-13T00:27:50.798Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- official-fix
- Vendor Advisory Urls
- [{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40403","vendor":"Microsoft"}]
Threat ID: 6a036557cbff5d861008c9b8
Added to database: 05/12/2026, 17:37:27 UTC
Last enriched: 06/19/2026, 17:39:00 UTC
Last updated: 07/31/2026, 19:22:58 UTC
Views: 111
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