It would be good to know. I’ve used an HDRI image for scene lighting in some of the renders I’m considering to submit.
The HDRIs come from https://polyhaven.com/ which are CC0 licensed (polyheaven license page) .
One thing that stands out to me is:
Once the creator or a subsequent owner of a work applies CC0 to a work, the work is no longer his or hers in any meaningful sense under copyright law. Anyone can then use the work in any way and for any purpose, including commercial purposes […] Think of CC0 as the “no rights reserved” option. CC0 is a useful tool for clarifying that you do not claim copyright in a work anywhere in the world.
If this is not OK I will have to either rework or discard the renders using HDRIs.