Microsoft Excel KB5002914 Update Breaks Copy and Paste for Some Users

Users of Microsoft Excel have reported that the Office security update known as KB5002914 for this week is causing problems with copy-and-paste functions and formula dragging, as stated in posts on Reddit and in the Microsoft Q&A forums. These users claim that normal operation is restored when the update is uninstalled or rolled back. The security update was issued by Microsoft as part of its September 2026 Patch Tuesday.