How to sign out of my iCloud on all devices

Read this document to learn how to sign out of iCloud on your iPhone, iPad, iPod touch, Apple TV, or Mac --> Sign out of iCloud on your iPhone, iPad, iPod touch, Apple TV, or Mac - Apple Support

If you can't connect or sign in to iCloud read the document at this link --> If you can't connect or sign in to iCloud - Apple Support

The poster's question is how to sign out of ALL devices. That implies all devices AT THE SAME TIME from one device with admin privileges. Its assumed anyone knows how to do it one at a time. The article link is a diversion.

And this is a concern for a larger problem that when you delete a device from appleid or change the password, neither automatically signs out other devices or signs out rogue/unknown devices.