CVE-2026-55045 Details

A vulnerability allowing out-of-bounds read has been identified in Microsoft Office. This issue could enable an unauthorized attacker to execute code locally. The vulnerability is present in several Microsoft Office products, including Office 365 for Mac, Office 2016 (both 32-bit and 64-bit editions), Office LTSC for Mac 2024, Office LTSC 2024 for 32-bit and 64-bit editions, Office LTSC 2021 for 32-bit and 64-bit editions, Office LTSC for Mac 2021, and SharePoint Server Subscription Edition. Additionally, Microsoft 365 Apps for Enterprise (both 32-bit and 64-bit systems) and Microsoft Office 2019 (also in 32-bit and 64-bit editions) are affected. In the case of SharePoint Server 2019 and SharePoint Enterprise Server 2016, this vulnerability also allows for remote code execution.

Users can download the security update for their specific version of Microsoft Office or SharePoint Server. For Office 365 for Mac, the update is available through the Microsoft Update Catalog. For Office 2016, 2019, and LTSC versions, the security update can also be downloaded from the Microsoft Update Catalog. SharePoint Server users can find the security update on the Microsoft Download Center.