Koel: Full-read SSRF via podcast enclosure URL: isPublicHost() filter_var guard does not reject NAT64 (64:ff9b::/96) or 6to4 (2002::/16) IPv6-transition wrappers of internal IPv4

Koel is a free, open-source music streaming solution. Prior to 9.7.1, App\Helpers\Network::isPublicHost() uses filter_var() with FILTER_FLAG_NO_PRIV_RANGE and FILTER_FLAG_NO_RES_RANGE, which treats NAT64 64:ff9b::/96 and 6to4 2002::/16 wrappers of private, loopback, or link-local IPv4 addresses as public. An authenticated user can place such an address in a podcast RSS <enclosure url> and reach app/Values/Podcast/EpisodePlayable.php through EpisodePlayable::createForEpisode(), where isSafeUrl() accepts the target and Http::sink($file)->get($url) fetches it. On a host with NAT64 or 6to4 routing, Koel can request internal services or cloud metadata and return the response body to the user. This issue is fixed in version 9.7.1