CVE-2026-100901A vulnerability was found in athlon1600 youtube-downloader up to 4.0.1. Affected by this vulnerability is the function stream of the file public/stream.php. The manipulation of the argument url results in server-side request forgery. It is possible to launch the attack remotely. The exploit has been made public and could be used. Commit 6ffe823 'better security for public/stream.php' only added CURLOPT_PROTOCOLS http/https restriction and MAXREDIRS cap, does not restrict destination host. The vendor was contacted early about this disclosure but did not respond in any way.