CVE-2026-55044 Details

A vulnerability allowing out-of-bounds read has been identified in Microsoft Office Excel. This issue enables an unauthorized attacker to execute code locally. The vulnerability is present in several versions of Microsoft Excel, including Excel 2016, Excel 2019, Office LTSC 2021, Office LTSC 2024, and various editions of Microsoft 365 Apps for Enterprise. The root cause of the vulnerability is an out-of-bounds read, which can be exploited by sending a malicious Office file to a user and convincing them to open it.

Users can download the security update for this vulnerability through the Microsoft Update Catalog. For Office LTSC 2024, updates are available for both 32-bit and 64-bit editions. Microsoft 365 Apps for Enterprise users can also download the security update through the Microsoft Update Catalog. For Excel 2016, security updates are available for both 32-bit and 64-bit editions.