# Microsoft's Excel Paste Bug Gets a Messy, Partial Fix for 2016 Users

> Microsoft released a partial hotfix for the Excel silent paste bug, but it only applies to Excel 2016 and struggles with conditional formatting.

- Canonical URL: https://coreiten.com/en/article/microsofts-excel-paste-bug-gets-a-messy-partial-fix-for-2016-users
- Language: en
- Section: Excel
- Author: Sami
- Published: 2026-09-21T20:01:55+03:00
- Modified: 2026-09-21T20:01:55+03:00
- Publisher: CoreITen (https://coreiten.com)
- Keywords: Excel 2016, Microsoft, Excel 2024, Paste Special, Microsoft Defender Antivirus, Windows Security

## Summary

Microsoft rolled out a partial hotfix for an Excel copy-and-paste bug, but left newer software versions temporarily unpatched.

- A September security update meant to fix remote code execution and information disclosure vulnerabilities inadvertently broke clipboard functionality in Excel.
- The new hotfix exclusively targets Excel 2016, leaving users of Excel 2024, 2021, and 2019 still waiting for a patch.
- Microsoft warned that pasting may still fail in workbooks containing conditional formatting rules even after installing the hotfix.
- An August update caused Windows Security to falsely report that Microsoft Defender Antivirus was disabled until it was resolved on September 17.

**Why it matters:** This incident highlights ongoing quality assurance challenges in Microsoft's rapid-release security pipeline, causing frustrating disruptions for enterprise workflows.

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Microsoft has released a partial hotfix for a frustrating bug that causes copy-and-paste operations to fail silently in Excel. The patch arrives weeks after a September security update, which was designed to address remote code execution and information disclosure vulnerabilities, inadvertently broke core clipboard functionality across multiple versions of the spreadsheet software.

Users attempting to paste data find that the source remains selected while the destination cell remains completely unmodified. The failure occurs without any system warning, error message, or alert beep, leaving users confused about why their data did not transfer. While the original broken update affected Excel 2024, 2021, 2019, and 2016, this new hotfix exclusively targets Excel 2016.

### Workarounds and Update Limitations

For users relying on newer versions of the software, or those who have applied the Excel 2016 hotfix, the clipboard functionality remains unstable. Microsoft has explicitly warned that the patch may still fail when interacting with specific spreadsheet features.

- **Conditional Formatting:** Pasting may still fail in workbooks that contain conditional formatting rules, even after the Excel 2016 hotfix is installed.
- **The Paste Special Workaround:** For users on Excel 2024, 2021, and 2019 who are still waiting for a patch, utilizing the Paste Special command can successfully bypass the bug in some scenarios.

### A Month of Broken Updates

The Excel clipboard issue is part of a broader pattern of problematic September updates from Microsoft. The primary September Windows security update required an emergency out-of-band release to fix multiple system issues, including a bug that left certain USB audio devices completely silent.

Additionally, an August update introduced a bug that caused Windows Security to falsely report that Microsoft Defender Antivirus was disabled. Microsoft finally resolved that specific false-positive issue in a dedicated Defender update released on September 17, while also adding new domain-joined device problems to its known issues tracker.

### The Cost of Rushed Security Patches

The rollout of this Excel hotfix highlights a growing QA testing problem within Microsoft's rapid-release security pipeline. By rushing to patch severe remote code execution vulnerabilities, the company is increasingly breaking fundamental UI operations - like basic copy-and-paste - that disrupt daily enterprise workflows.

Furthermore, prioritizing a hotfix for the legacy Excel 2016 while leaving users of the current Excel 2024 and 2021 versions stranded is an inverted patching strategy. It suggests that the underlying codebase divergence between the perpetual license versions is severe enough that a unified patch was impossible, forcing IT administrators to manage fragmented workarounds across different departments.

## Sources

- [theregister.com](https://www.theregister.com/software/2026/09/18/microsoft-fixes-the-fix-that-broke-excel-paste-partly/5297467)

## Related topics

- [Windows Security](https://coreiten.com/en/topic/windows-security)