This vulnerability (CVE-2026-44818) involves a race condition (CWE-362) in Microsoft Office Excel as part of Microsoft 365 Apps for Enterprise. Improper synchronization during concurrent execution of shared resources can enable an unauthorized attacker to execute code locally. The CVSS v3.1 base score is 7.0, indicating high severity, with attack vector local, high attack complexity, no privileges required, and user interaction required. 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 unauthorized local attacker to execute arbitrary code on the affected system, potentially leading to full compromise of the user environment. The vulnerability impacts confidentiality, integrity, and availability with high impact levels. However, exploitation requires local access and user interaction, and the attack complexity is high.

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 patched version as per Microsoft's advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-44818. No additional mitigation actions are required beyond applying the official fix.