CVE-2026-97004: CWE-122: Heap-based Buffer Overflow in Microsoft Microsoft 365 Apps for Enterprise

This vulnerability (CVE-2026-97004) is a heap-based buffer overflow in Microsoft Office Excel, part of Microsoft 365 Apps for Enterprise. It enables remote code execution by an unauthorized attacker over a network. The CVSS 3.1 base score is 8.8, indicating high severity with network attack vector, low attack complexity, no privileges required, user interaction required, and impacts on confidentiality, integrity, and availability. Microsoft has issued an official fix and manages remediation for this cloud service. No active exploitation has been reported.

Successful exploitation of this vulnerability could allow an attacker to execute arbitrary code remotely on affected systems, potentially leading to full compromise of confidentiality, integrity, and availability of the affected Microsoft 365 Apps for Enterprise environment. However, no known exploits are currently active in the wild.

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-2026-97004 to ensure protection.