CVE-2026-54008 Open WebUI: Redirect-Bypass SSRF in OAuth `_process_picture_url`

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.6, backend/openwebui/utils/oauth.py::processpictureurl calls validateurlpictureurl on the initial URL only, then invokes aiohttp.ClientSession.getpictureurl, ... without...