What happened? Due to the recent XZ-Utils drama I checked the code and I'm appalled. There are more BLOBS than source code. https://github.com/ventoy/Ventoy/tree/3f65f0ef03e4aebcd14f233ca808a4f8946...
I had no idea this issue had been identified. While I find this tool very useful, the project is seeming rather questionable to me now.
Because ventoy supports shim, and by extension secure boot, these files needs to come from a signed Linux distro. In this case they are taken from Fedora releases, and OpenSUSE apparently, as they publish shim binaries and grub binaries signed by their certificate.
I think they did say that in the older thread. But for proper security, you shouldn't have to trust them. You should have build tools that will re-fetch everything to create an identical build. That gives a clear chain of custody, which proves that morning has been tampered with.