"PRO DJ LINK" enables you to access rekordbox libraries (and load music files) remotely from other devices, whether that be on a computer or dedicated Pioneer/AlphaTheta hardware.
The vulnerability in question requires the attacker to be on the same local network as the instance of rekordbox and for the remote library feature to be enabled. Interested in the full writeup once it's released
Rather than trying to make a new, shiny library, they should just release rekordbox 2.0, and then everyone would have a common lexicon to ask whether something is “rekordbox 2 compatible”. But instead we have this questionably compatible library plus as part of old, busted software that tries to brow best you into wrecking your old libraries.
I just use Claude to explain rekordbox to me now, and it is a bit more helpful than forums, though it also often gets confused from the conflicting advice/docs on the internet