This vulnerability (CVE-2026-64915) is a heap-based buffer overflow in Microsoft Office Word, part of Microsoft 365 Apps for Enterprise. It enables an unauthorized attacker to execute code locally, potentially leading to full compromise of confidentiality, integrity, and availability. The CVSS 3.1 score is 7.8, reflecting high impact with local attack vector, low attack complexity, no privileges required, and user interaction needed. Microsoft has published an official fix and manages remediation for this cloud service. The affected version explicitly identified is 16.0.1.

Successful exploitation allows local code execution by an unauthorized attacker, resulting in high impact on 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 remediation server-side. Users and administrators should apply the official update as directed in the Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-64915 to mitigate this vulnerability.