This vulnerability involves a heap-based buffer overflow in the Windows Desktop Window Manager (DWM) Core Library in Windows 11 version 26H1 (build 10.0.28000.0). An authorized attacker with local access can exploit this flaw to elevate their privileges, potentially gaining higher-level system rights. The vulnerability is tracked as CVE-2026-44811 and is classified under CWE-122 (Heap-based Buffer Overflow). Microsoft has published an official security update to remediate this issue.

Successful exploitation allows an authorized local attacker to elevate privileges, potentially leading to full system compromise or unauthorized actions requiring higher privileges. The vulnerability affects confidentiality, integrity, and availability as indicated by the CVSS vector (C:H/I:H/A:H). There are no known exploits in the wild at this time.

An official fix is available from Microsoft. Users and administrators should apply the security update provided by Microsoft for Windows 11 version 26H1 (build 10.0.28000.0) as soon as possible to remediate this vulnerability. Refer to the Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-44811 for detailed update instructions.