CVE-2026-69442: CWE-122: Heap-based Buffer Overflow in Microsoft Microsoft 365 Apps for Enterprise

This vulnerability, tracked as CVE-2026-69442 and classified under CWE-122 (heap-based buffer overflow), affects Microsoft 365 Apps for Enterprise. It allows remote code execution by an unauthorized attacker due to improper handling of memory on the heap. The flaw can be triggered over a network without privileges and requires user interaction. The CVSS 3.1 vector indicates network attack vector, low attack complexity, no privileges required, user interaction required, and impacts confidentiality, integrity, and availability with high severity. Multiple version ranges prior to patched builds are affected. Microsoft has released an official fix for this vulnerability.

Successful exploitation of this vulnerability could allow an attacker to execute arbitrary code remotely on the affected system, potentially leading to full compromise including confidentiality, integrity, and availability impacts. The vulnerability requires user interaction but no privileges or authentication, increasing its risk in networked environments.

An official fix is available from Microsoft. Users and administrators should apply the security updates provided by Microsoft for Microsoft 365 Apps for Enterprise as detailed in the vendor advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-69442. Since this is a cloud service as well, Microsoft manages remediation for the cloud-hosted components. No additional mitigation actions are specified by the vendor.