Firefox was updated to v. 72 this week, then an update to 72.0.1 was very quickly pushed out. Turns out there was a serious security bug that was actively being exploited by cybercriminals for a while -- not just something that was introduced with v. 72.
If you use Firefox, click Help -> About Firefox to make sure your copy has been updated. If you use the TOR browser, v. 9.0.4 has been released to fix the same problem.