AsNoriuanswered grow question 2y ago I feel your pain ...
But , if it was in jar for few days or more, i would chuck all out, even jar itself.
Mould multiply by air with spores, you dont know what was infected and what will be.
Be careful if you have grow going, having it on paper to dry makes all room infected ...
There will be more advices, i see you understand what bud rot is, you found it inside of bud, but still, as i said you dont know what was infected and what you will infect ....
I would take loses now and prevent even theoretical spread possibility...