Microsoft admits September 2026 Excel update disrupts copy‑paste functionality

Microsoft has officially confirmed that the copy‑and‑paste feature may stop working for some Excel users after they install the September 2026 security update identified as KB5002914.

The problem first came to public attention through a report by the security‑focused site bleepingcomputer, which described users experiencing silent failures – the clipboard appears to accept data but nothing is transferred when pasting inside Excel.

In a brief statement, Microsoft acknowledged the defect, noting that it appears to affect a limited set of system configurations. The company is developing a remedial patch and advises anyone impacted to uninstall the KB5002914 update or roll back to the previous version until a fix is released.

Copy‑and‑paste is a fundamental operation in Excel, used for everything from simple data entry to complex analysis and reporting. An interruption can therefore hinder routine workflows, delay project timelines, and create extra steps for users who must resort to manual re‑typing or alternative transfer methods.

The incident underscores the difficulty of delivering cumulative monthly updates to a diverse global user base. Microsoft typically rolls out security patches on the second Tuesday of each month, and when regressions surface, it aims to issue corrective updates within a few weeks. IT administrators are encouraged to keep an eye on Microsoft’s release notes and to test future updates in controlled environments before broad deployment.