0patch is now starting “micropatching” for Office 2021

Microsoft Office 2021 will soon officially no longer receive security updates – but with 0patch from Acros Security there is an unofficial, paid alternative as a bridge solution for everyone who wants to use their existing installation securely for longer.

Office 2021 continues to run – but only with additional costs

On October 13, 2026, Microsoft will end support for Office 2021. From then on there will be no more security updates. If you want to continue using the suite, you can switch to new ones, similar to outdated versions of Windows 0patch updates from the Slovenian company Acros Security. The company is offering “unofficial” security patches for at least three more years – without rebooting and without changing the original Office files. This is what Neowin reports.

What happens on October 13, 2026

On this day, Microsoft is ending the life cycle of Office LTSC 2021 and the retail version Office 2021 for Windows and Mac. Word, Excel, PowerPoint, Outlook, Access and other programs will no longer receive security updates, bug fixes or technical support. The software remains operational, but newly discovered vulnerabilities are no longer closed. Unlike Windows 10, there is no Extended Security Updates program (ESU) from Microsoft for Office 2021. Microsoft recommends Microsoft 365 (cloud subscription) or the newer perpetual version Office 2024 as an upgrade. LibreOffice is often mentioned as an alternative.

0patch: This is how “micropatching” works

0patch works differently than classic updates. Instead of exchanging entire DLL or EXE files, the service injects tiny code fragments – so-called micropatches – directly into the RAM of running processes. The original Office binaries on disk remain unchanged. Users do not have to restart the PC or Office programs when a patch is applied. According to the provider, the patches can be removed just as quickly if problems arise. In terms of content, 0patch focuses on critical security vulnerabilities that are likely to be actively exploited after October 13, 2026. The approach is similar to “virtual patching” or “vulnerability shielding” known in IT security: exploit attempts are intercepted without changing the actual program code.

Costs and target group

Office 2021 support is included in the paid PRO and Enterprise plans. For Enterprise, 0patch currently quotes 34.95 euros plus tax per computer and year. The plan is aimed at medium and large organizations and offers features such as central administration, roles, computer groups, group-based patch policies and single sign-on. The plans also cover other security patches, for example for Windows versions whose official support has already expired – all under one license. According to the provider, 0patch only provides security patches and support for its own service, not general technical help for Office 2021.

What this means for users

0patch offers an option to operate Office 2021 more securely beyond the official end of support date – but for a fee and with a focus on critical gaps, not on convenience updates or new functions. Whether this is worth it depends on the individual risk assessment, the planned upgrade roadmap and the costs of switching to Microsoft 365 or Office 2024.