CVE-2026-97012: CWE-121: Stack-based Buffer Overflow in Microsoft Microsoft 365 Apps for Enterprise

This vulnerability (CVE-2026-97012) is a stack-based buffer overflow in Microsoft Office Outlook within 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, and user interaction required. The vulnerability affects versions =16.0.1, >=16.0.1 <16.0.14334.20974, and >=16.0.0 <16.0.17932.21056. Microsoft has published an official fix and manages remediation for this cloud-hosted service. No known exploits are reported in the wild at this time.

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

An official fix is available from Microsoft. Users and administrators should apply the security updates provided in the Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-97012. Since this is a cloud service, Microsoft manages remediation server-side, but customers should verify their client versions are updated to non-vulnerable builds.