Hi, was this on a Mac or on an iPhone/iPad (iOS device)? There definitely is an update out for "Desktop" versions of Firefox (Mac, Windows, Linux) today -- version 129. If you have Firefox set to notify you about updates, then you would get a familiar little drop-down from the menu button. If you got some other kind of notice, hmm, maybe that's a new thing?? If in doubt, of course, you may want to scan your system for malware. Malwarebytes for Mac is a common recommendation (it has a free trial).