In early December a cybersecurity threat was discovered with the popular “log4j” utility. The Post has a good piece on the exploit, explained in non-jargon.
The fact that log4j is such a ubiquitous piece of software is what makes this such a big deal. Imagine if a common type of lock used by millions of people to keep their doors shut was suddenly discovered to be ineffective. Switching a single lock for a new one is easy, but finding all the millions of buildings that have that defective lock would take time and an immense amount of work.