FOSS is a specified exception in the CRA. Am I missing something?
https://pyfound.blogspot.com/2023/04/the-eus-proposed-cra-la...
to wit: under a reasonable reading of the legislation, having any commercial activity (classes, conference tickets, etc) opens you to liability. Or imagine selling support.
Additionally: if open source code is included by someone besides the author into a commercially available product, it's not clear that the open source author doesn't hold liability there. Even if the author received $0, or is unaware of the use of the software he/she created.