GoKawiilMicrosoft patches Excel copy-paste bug caused by September 2026 security updates
Microsoft has released fixes for a bug that silently broke copy-and-paste, autofill, and formula dragging in Excel after installing this month's security updates, including KB5002914. Users of Excel 2016, Office LTSC 2019, 2021, and 2024 must manually install specific updates to resolve the issue, which had been widely reported on Reddit and Microsoft's Q&A forums.
GoKawiil's interpretation of the reporting above, not reported fact.
Silent failures are especially disruptive because users have no indication their work wasn't saved or pasted correctly, risking data loss in spreadsheets relied on for business operations. This is part of a recurring pattern of Office regressions this year, suggesting quality control gaps in Microsoft's update pipeline that require manual intervention from IT admins and users to fix.
- Manual updates like KB5002665 are required across multiple Excel and Office LTSC versions to fix the bug.
- Paste failures with conditional formatting in workbooks remain unresolved, requiring a 'Paste Special' workaround.
- This is the third major Office functionality bug Microsoft has fixed in 2026 following issues in June and July.
Source: bleepingcomputer.com, 2026-09-21
Published there as: “Microsoft fixes broken Excel copy and paste for all Office users”
Read the original report → The summary and analysis above are GoKawiil's own, written from reporting by the source above. Facts and quotes belong to the original publisher.