Microsoft has released an urgent security update on January 26, 2026, for Microsoft Office 2016 and Microsoft Office 2019. They’re pleading for anybody using either software suite to immediately download the latest software patch to avoid a high-risk vulnerability before hackers can exploit it.

Because the vulnerability is marked as fairly severe, you should waste no time in making sure that your copy of Office is secure. This is aimed only at the offline Office suite of apps, not the online Microsoft Office 365 suite that operates within the cloud.

Why You Need to Update Microsoft Office ASAP

The vulnerability affects a Microsoft Office software suite from 2016 and later, although customers using the latest versions of Office won’t have to do anything on their part. It’s only those using older versions that have to take action themselves.

“Customers running Office 2021 and later will be automatically protected via a service-side change, but will be required to restart their Office applications for this to take effect,” wrote Microsoft.

“Customers running Office 2016 and 2019 are not protected until they install the security update. Customers on these versions can apply the registry keys described as follows to be immediately protected.”

If you run Office 2021 or Office 2024, go ahead and close your Office app, and then reopen it. That way, you can be extra sure that you’ve kick-started the protection that the automatic server-side change ensures.

And if you run Office 2016 or Office 2019, then go into the app’s settings to check for updates as soon as possible, and then download them. Until then, be careful which files you open in any of the Office programs, including (but not limited to) Word, PowerPoint, and Excel.

In order for the attacker to gain entry into your computer through the vulnerability, they have to first send you a malicious Office file and convince you to open it. So stay skeptical, and be triple sure of any file you open in Office until you download the software patch.