CVE-2026-69759: CWE-121: Stack-based Buffer Overflow in Microsoft Microsoft 365 Apps for Enterprise

This vulnerability is a stack-based buffer overflow (CWE-121) in Microsoft Office Word, part of Microsoft 365 Apps for Enterprise. It enables remote code execution by an unauthorized attacker over a network. The CVSS 3.1 score is 8.8, indicating high severity with network attack vector, low attack complexity, no privileges required, and user interaction required. The vulnerability affects several version ranges of Microsoft 365 Apps for Enterprise prior to fixed versions. Microsoft has issued an official fix and manages remediation for this cloud-hosted service. No known active exploits have been reported.

Successful exploitation allows an attacker to execute arbitrary code remotely, potentially leading to full compromise of the affected system. The vulnerability impacts confidentiality, integrity, and availability with high severity. However, exploitation requires user interaction.

An official fix is available from Microsoft. Users and administrators should apply the latest security updates for Microsoft 365 Apps for Enterprise as provided in the Microsoft Security Response Center advisory. Since this is a cloud service, Microsoft manages remediation server-side, but client updates should be applied promptly to ensure protection.