CVE-2026-33332: NiceGUI's unvalidated chunk size parameter in media routes can cause memory exhaustion

NiceGUI’s app.add_media_file() and app.add_media_files() media routes accept a user-controlled query parameter that influences how files are read during streaming. The parameter is passed to the range-response implementation without validation, allowing an attacker to bypass chunked streaming and force the server to load entire files into memory at once.

With large media files and concurrent requests, this can lead to excessive memory consumption, degraded performance, or denial of service.