CVE-2026-28414: Gradio has Absolute Path Traversal on Windows with Python 3.13+

Gradio is an open-source Python package designed for quick prototyping. Prior to version 6.7, Gradio apps running on Window with Python 3.13+ are vulnerable to an absolute path traversal issue that enables unauthenticated attackers to read arbitrary files from the file system. Python 3.13+ changed the definition of `os.path.isabs` so that root-relative paths like `/windows/win.ini` on Windows are no longer considered absolute paths, resulting in a vulnerability in Gradio's logic for joining paths safely. This can be exploited by unauthenticated attackers to read arbitrary files from the Gradio server, even when Gradio is set up with authentication. Version 6.7 fixes the issue.