CVE-2026-108431: CWE-121: Stack-based Buffer Overflow in Microsoft Microsoft 365 Apps for Enterprise

This vulnerability (CVE-2026-108431) is a stack-based buffer overflow 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 v3.1 score is 8.8, indicating high severity with network attack vector, low attack complexity, no privileges required, and user interaction required. The vulnerability affects multiple versions prior to the fixed builds specified by Microsoft. Microsoft has released an official fix and manages remediation for this cloud service. No active exploitation has been reported.

Successful exploitation allows an attacker to execute arbitrary code remotely with high impact on confidentiality, integrity, and availability. This could lead to full system compromise of affected Microsoft 365 Apps for Enterprise installations.

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 updates as directed in the Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-108431 to ensure protection.