This vulnerability (CVE-2026-64912) is a stack-based buffer overflow in Microsoft Office Access, part of Microsoft 365 Apps for Enterprise. It enables an unauthorized attacker to execute arbitrary code locally, potentially leading to full compromise of the affected system. The vulnerability requires low attack complexity and no privileges but does require user interaction. Microsoft has published an official fix and manages remediation for this cloud service. No known exploits are currently reported in the wild.

Successful exploitation can result in complete confidentiality, integrity, and availability compromise of the affected system due to local code execution. The attacker does not require privileges but must convince a user to interact with a malicious file or content. This could lead to full system compromise or data loss on the affected endpoint.

An official fix is available from Microsoft. Since this is a cloud-hosted service, Microsoft manages remediation server-side. Users and administrators should ensure their Microsoft 365 Apps for Enterprise are updated to the fixed version as per Microsoft's guidance at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-64912.