If you'd like to FIX a bug in Zen Cart that you (or someone else) has reported, your PR is welcome! Zen Cart is stored in Github at:
https://github.com/zencart/zencart
Please submit your PR to the latest branch. If it needs to get backported for a possible prior-version release, the team will take care of that for you.
If you have never used Github or contributed to an open source project, here is some getting started information:
https://docs.zen-cart.com/
