CVE-2026-69544: CWE-122: Heap-based Buffer Overflow in Microsoft Windows 11 version 26H1

This vulnerability (CVE-2026-69544) involves a heap-based buffer overflow in the Windows SMB Client component of Microsoft Windows 11 version 26H1. An attacker with local authorized access can exploit this flaw to elevate their privileges on the affected system. The issue is tracked under CWE-122 (Heap-based Buffer Overflow). Microsoft has published an official fix to address this vulnerability.

Successful exploitation allows an authorized local attacker to elevate privileges, potentially gaining higher-level access to the system. 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 to remediate this vulnerability. Refer to the Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-69544 for update details.