Microsoft confirmed that its September 2026 KB5002914 security update breaks copy and paste in Excel, with no fix yet available. The bug fails silently, giving users no error or warning when it strikes.
The Big Picture
- Microsoft confirmed KB5002914 causes paste operations to fail silently in Excel 2024, 2021, 2019, and 2016.
- The source stays selected and the destination stays unmodified, with no beep or error message shown.
- Microsoft traced the cause to a code regression in a recent service update and is still researching a fix.
- Affected users have found that uninstalling KB5002914 restores copy and paste on their systems.
- The bug follows Remote Desktop Services, Hyper-V, and USB audio failures that Microsoft also fixed this week from the same September update cycle.
KB5002914 Breaks Excel’s Paste Function
Complaints surfaced on Reddit and the Microsoft Q&A forums within days of the KB5002914 rollout, with users describing copy and paste, autofill, and formula dragging all failing without warning.
Microsoft confirmed the problem in an updated support document. “Although users try to paste content, the source remains selected and the destination is unmodified,” the document states. “When this issue occurs, users receive no indication of the failure, such as a beep or error message.“
In a service alert, Microsoft attributed the fault to a code regression. “A code regression contained within a recent service update is causing impact,” the alert states. “Our development and validation of the individual fixes targeting each of the impacted versions is ongoing.”
Excel 2016 update bug
by u/Commercial_Twist_574 in excel
A Temporary Workaround Exists
Microsoft has not shipped a patch, but affected users have found that rolling back KB5002914 restores normal paste behavior. The rollback commands differ by Office version and run from an elevated Command Prompt window.
For Office 2016, the command removes the patch directly through the Office Deployment tool. For Office 2019, 2021, and 2024, the fix uses the Click-to-Run client to step the installation back to a version predating the update. Running the wrong command for a given Office build will not resolve the issue, so users should confirm their version first.
A Rough Patch Tuesday for Microsoft
The Excel bug lands during a September 2026 Patch Tuesday cycle that also triggered failures in Remote Desktop Services, Hyper-V, and USB audio, which Microsoft resolved this week through an emergency out-of-band update. That September update carried close to 1,000 security fixes across the Windows and Office ecosystem, making it one of the larger monthly cycles of the year.
It also continues a pattern of Office reliability issues stretching back several months. In July, Microsoft fixed a bug preventing Word, Excel, PowerPoint, and Access from launching on updated Windows 11 systems. In June, a separate issue blocked Office for the web users from opening Excel and PowerPoint files, and another stopped Windows 365 users from installing the Office suite at all.
What’s Next?
The pattern points to gaps in Microsoft’s update validation process rather than a single bad patch. Multiple Office and Windows reliability failures across the past three months, each traced to a different component, suggest the regression testing pipeline is not catching interactions between security fixes and core application behavior before release.
For anyone on Excel 2016 through 2024 who relies on copy and paste, autofill, or formula dragging for daily work, the practical move right now is to check whether KB5002914 is installed and roll it back using Microsoft’s Click-to-Run or Office Deployment commands if paste operations are failing silently. IT administrators managing fleets should hold off deploying KB5002914 broadly until Microsoft publishes a validated fix, since the support document offers no timeline yet. Microsoft says it will update its support article once a resolution path is confirmed.
