Microsoft Patch KB5002914 Breaks Copy‑Paste in Excel 2016, Fix Released via KB5002665
What Happened — The September 2026 security update KB5002914 caused copy‑and‑paste, autofill, and formula‑dragging operations to fail silently in Microsoft Excel 2016 (MSI‑based edition). Microsoft released a corrective update KB5002665 that restores the functionality for the affected edition.
Why It Matters for Trust & Control Assurance
- Functional regressions after a security patch illustrate the need for change‑management controls that require testing and validation before production rollout.
- Continuous control‑assurance programs must capture evidence of patch verification and maintain a rollback plan to preserve audit‑ready evidence of remediation.
- The incident maps to the control objective of ensuring the effectiveness of configuration and change controls, a single control that satisfies multiple frameworks (e.g., NIST CSF 2.0, ISO 27001).
Who Is Affected — Enterprises and end‑users across all sectors that rely on Excel 2016 (MSI edition), particularly finance, engineering, and government offices that depend on spreadsheet automation.
Recommended Actions
- Deploy the KB5002665 fix to affected machines; verify remediation in a test environment before full rollout.
- Document the regression, the mitigation steps, and the rollback procedure as part of your change‑management evidence.
- Update your patch‑validation SOPs to include functional testing of critical productivity tools after each security update.
Source: BleepingComputer
Technical Notes
- The regression stems from a code change in the September 2026 security update (KB5002914).
- The issue affects Excel 2016 MSI, Excel 2019/2021/2024, and Excel Online, but the fix currently only covers the MSI edition.
- Uninstalling KB5002914 restores functionality but also removes critical security patches for remote‑code‑execution vulnerabilities.
Source: Microsoft support documentation