CVE-2026-72973: CWE-122: Heap-based Buffer Overflow in Microsoft Microsoft 365 Apps for Enterprise

This vulnerability (CVE-2026-72973) is a heap-based buffer overflow in Microsoft Office Word component of Microsoft 365 Apps for Enterprise. It enables remote code execution by an unauthorized attacker over a network. The vulnerability affects multiple version ranges of Microsoft 365 Apps for Enterprise prior to the fixed versions indicated. Microsoft has published an official fix and manages remediation for this cloud service. The CVSS 3.1 score is 8.8, indicating high severity with network attack vector, low attack complexity, no privileges required, user interaction required, and high impact on confidentiality, integrity, and availability.

Successful exploitation of this vulnerability could allow an attacker to execute arbitrary code remotely on affected systems, potentially leading to full compromise of the affected Microsoft 365 Apps for Enterprise environment. The impact includes complete loss of confidentiality, integrity, and availability of the affected application.

An official fix is available from Microsoft. Since this is a cloud-hosted service, Microsoft manages remediation server-side. Users and administrators should follow the guidance in the Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-72973 to ensure their environments are updated to the fixed versions. No additional mitigation actions are required beyond applying the official update.