This vulnerability (CVE-2026-55056) involves a heap-based buffer overflow in Microsoft 365 Apps for Enterprise, enabling an unauthorized attacker to execute code locally. The CVSS 3.1 vector indicates the attack requires local access with low complexity and no privileges but user interaction is required. The impact includes high confidentiality, integrity, and availability consequences. Microsoft has published an official fix and manages remediation for this cloud service. No active exploitation has been reported.

Successful exploitation could allow an attacker to execute arbitrary code locally, potentially leading to full compromise of the affected application environment. The vulnerability affects confidentiality, integrity, and availability at a high level. However, exploitation requires local access and user interaction.

An official fix is available from Microsoft. Since this is a cloud-hosted service, Microsoft manages remediation server-side. Users and administrators should ensure that updates are applied as per the Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55056 to mitigate this vulnerability.