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
https://github.com/koel/koel/security/advisories/GHSA-rjg7-r26h-cfp2
https://github.com/koel/koel/releases/tag/v9.7.1
https://github.com/koel/koel/pull/2549
https://github.com/koel/koel/commit/5f6ce2cefd08f437a269236b677ad971517ccbb6
Published: 2026-08-19
Updated: 2026-08-19
Base Score: 5
Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:N
Severity: Medium
Base Score: 7.5
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Severity: High
Base Score: 5.3
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
Severity: Medium
EPSS: 0.00272