CVE-2026-71212: Improper Neutralization of Argument Delimiters in a Command

xidown a yt-dlp/ffmpeg GUI wrapper builds its yt-dlp command-line invocation xidown/core/scanner.py and downloader.py by appending the user-provided or scanned URL as a bare trailing positional argument, with no '--' end-of-options marker and no scheme validation anywhere in the codebase...