It's the second Tuesday of the month, and you know what that means. It's Patch Tuesday, so if it's made by Microsoft and it's supported, it's getting an update today. For most Windows 10 users, that includes versions 2004, 20H2, and 21H1, although Windows Insiders that are testing 21H2 will get the same update. That's because all of these versions of the OS are really the same bits, just separated by an enablement package.

Indeed, they're all getting the exact same cumulative update, which is KB5005565, and that brings the build number to 19044.1237, 19043.1237, 19042.1237, or 19041.1237, depending on if you're on Windows 10 version 21H2, 21H1, 20H2, or 2004, respectively. You can manually download the update here, if you want to manually install it. The list of highlights is just security updates:

• Updates security for your Windows operating system.

As usual, the full list of fixes isn't super big. The larger changelog typically comes alongside the optional update that arrives later in the month, so if you didn't take that update, those fixes are just bundled into this one.

There are also certain older versions of Windows 10 that are still supported. These updates are only available under certain conditions. For example, Windows 10 version 1909 is only supported for Enterprise and Education SKUs, while versions 1507, 1607, and 1809 are only supported in the Long-Term Servicing Channel.

As usual for Patch Tuesday, these are mandatory updates. You can go to Windows Update and grab them right now, and if you don't, they'll be installed in the background at some point.