CVE-2026-55049 Details

A heap-based buffer overflow vulnerability has been identified in Microsoft Office. This vulnerability allows an unauthorized attacker to execute code locally. It affects several different versions and editions of Microsoft Office, including Office LTSC 2021, Office 2019, Office 365, and various Office for Mac versions. The vulnerability requires user interaction, as an attacker must send a malicious Office file and convince the user to open it. Additionally, the Preview Pane can be used to exploit this vulnerability.

Users can download the security update for their specific version of Microsoft Office. For Office LTSC 2021, updates are available through the Microsoft Update Catalog. Office 365 users can find the update via the Microsoft 365 Admin Center. Instructions for downloading the security update for Office 2016 are also available on the Microsoft Update Catalog.