CVE-2026-83903: CWE-122: Heap-based Buffer Overflow in Microsoft Windows 11 Version 24H2
Description
CVE-2026-83903 is a heap-based buffer overflow vulnerability in Windows Direct Composition affecting Windows 11 Version 24H2. It allows an authorized local attacker to elevate privileges. The vulnerability has a high severity score of 7.8 and has been officially fixed by Microsoft.
CVSS v3.1
Score 7.8high
Affected software
Microsoft
Windows 11 Version 24H2
Microsoft
Windows 11 Version 25H2
Microsoft
Windows 11 Version 26H2
Microsoft
Windows Server 2025
Microsoft
Windows Server 2025 (Server Core installation)
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CVE-2026-83903) involves a heap-based buffer overflow in the Windows Direct Composition component of Windows 11 Version 24H2. An authorized attacker with local access can exploit this flaw to elevate privileges on the affected system. The issue is tracked under CWE-122 and has a CVSS v3.1 base score of 7.8, indicating high severity. Microsoft has released an official fix for this vulnerability.
Potential Impact
Successful exploitation allows an authorized local attacker to elevate privileges, potentially gaining higher-level access on the affected Windows 11 Version 24H2 systems. This could lead to full system compromise depending on the privileges obtained.
Mitigation Recommendations
An official fix is available from Microsoft. Users and administrators should apply the security updates provided by Microsoft to remediate this vulnerability. Refer to the Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83903 for update details and installation instructions.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2026-08-31T23:21:53.301Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- official-fix
- Vendor Advisory Urls
- [{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83903","vendor":"Microsoft"}]
Threat ID: 6ace85252cdf04f6569fb1d2
Added to database: 10/13/2026, 19:23:17 UTC
Last enriched: 10/14/2026, 05:03:19 UTC
Last updated: 10/14/2026, 05:03:19 UTC
Views: 3
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