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

Successful exploitation of this vulnerability allows an authorized local attacker to gain elevated privileges, potentially leading to full system compromise. The CVSS v3.1 base score is 7.8, indicating high severity with high impact on confidentiality, integrity, and availability. No known exploits are reported in the wild at this time.

An official fix is available from Microsoft. It is recommended to 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 Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-44811 for detailed patch information and installation instructions.