Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.1.124, when attaching files to a promp, the name of the file is derived from the original HTTP upload request and is not validated or sanitized. This allows for users to upload files with names containing dot-segments in the file path and traverse out of the intended uploads directory. Effectively, users can upload files anywhere on the filesystem the user running the web server has permission. This vulnerability is fixed in 0.1.124.