CVE-2026-97751: CWE-122: Heap-based Buffer Overflow in Microsoft Microsoft 365 Apps for Enterprise

This vulnerability (CVE-2026-97751) 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 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 explicitly listed, and Microsoft has released an official fix. The vendor advisory is available at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-97751. There are no known exploits in the wild at this time.

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. Users and administrators should apply the vendor-provided patches as detailed in the Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-97751. Since this is a cloud-hosted service, Microsoft manages remediation server-side. No additional mitigation steps are indicated by the vendor.