This vulnerability is a stack-based buffer overflow (CWE-121) in Microsoft Office Word component of Microsoft 365 Apps for Enterprise version 16.0.1. It permits an unauthorized attacker to execute arbitrary code locally, potentially leading to full compromise of the affected system. The CVSS v3.1 base score is 7.8, reflecting high impact on confidentiality, integrity, and availability. Microsoft has published an official fix and manages remediation for this cloud service. No active exploitation has been reported.

Successful exploitation allows local code execution by an unauthorized attacker, which can compromise confidentiality, integrity, and availability of the affected system. This could lead to full system compromise if exploited.

An official fix is available from Microsoft. Since this is a cloud-hosted service, Microsoft manages the remediation process. Users and administrators should apply the official update as provided in the Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-64907 to mitigate this vulnerability.