[ynoxinul]

I've also noticed that clicking on "x" means "Install now", but in my case it asks for my password first and I can deny that, preventing the install.

[tumult]

It didn’t ask me for my password and it somehow was able to try to do it, anyway. I managed to stop it in time through sheer luck.

[crazygringo]

That has never happened for me. I click X whenever I get a "New software available" notification and it has never once downloaded or installed anything.

While clicking on the notification itself (not the X) brings you to the Software Update section in System Preferences.

But I've never once triggered an install from the notification directly. (I have auto-install and auto-download both off in case that affects it.)

[flutas]

I've had both happen unfortunately too.

Click the X, it instantly asks you for your password to update.

Click the X, it for some reason decides that means it needs to open the Software Update settings screen. (and no, I'm not accidentally misclicking. This happens daily in an OSX VM I have on my M1)

[crazygringo]

I think there's sometimes a bug with the X. I totally believe you're not misclicking.

The X button has always been weird because it's not visible until you hover, it has a weird fade in, it's way too tiny, and it seems like sometimes the notification registers a click rather than the X. It's bad all around, and I don't understand why they still haven't improved it.