A single internal post page has recieved 100's of backlinks from unrelated sites (pingbacks, comment spam).
Now instead of going through every single domain/page to disavow I'd like to disavow all links that are pointing towards that specific url. It's been already 404, but I'm certain the spam is still causing SEO damage, penalization from google.
404s do not pass Page Authority. However, if your site was penalized, then you need to submit a disavow list.
You can get a list of all the domains from Google Search Console -> Links - Top Linked pages - externally. Click the page you want to disavow links for, and then export the data.
https://support.google.com/webmasters/answer/2648487?hl=en for more info on how to submit a disavow list.