Ruby on Rails disclosed on HackerOne: XSS by file (Active Storage...

Hello, I've seen similar issues with #407319 and #429868 occur with Active Storage's new File serving strategies `Proxying`. Commit is https://github.com/rails/rails/commit/dfb5a82b259e134eac89784ac4ace0c44d1b4aee. ```ruby # https://github.com/rails/rails/blob/master/activestorage/app/controllers…