What You Need to Do: Microsoft has applied a server‑side fix for Office 2021 and Microsoft 365 Apps, but the protection is only applied after a restart of Office apps (Outlook, Word, PowerPoint, Excel, Teams) or a system reboot.
Please close all Office applications and reopen them as soon as possible. You may also reboot your computer for the same effect.
What We Are Doing: Our Information Security team is actively monitoring the situation, validating mitigation steps and will deploy official Microsoft patches as soon as they become available for all affected versions.