CVE-2026-97003: CWE-122: Heap-based Buffer Overflow in Microsoft Microsoft 365 Apps for Enterprise

This vulnerability (CVE-2026-97003) 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 impact on confidentiality, integrity, and availability. Microsoft has published an official fix and manages remediation for this cloud service. Affected versions include multiple builds of Microsoft 365 Apps for Enterprise around version 16.0, specifically versions =16.0.0, =16.0.1, and ranges >=16.0.0 <16.0.10417.20228, >=16.0.0 <16.0.17932.21056, and >=16.0.1 <16.0.14334.20974.

Successful exploitation allows an attacker to execute arbitrary code remotely without privileges, potentially leading to full compromise of the affected system. The vulnerability impacts confidentiality, integrity, and availability of the 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 latest updates as directed in the Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-97003 to ensure protection.