EUVD-2026-358647

fkie_cve-2026-54494

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

GHSA-rjg7-r26h-cfp2 — Koel: Full-read SSRF via podcast enclosure URL: isPublicHost() filter_var guard does not reject NAT64 (64:ff9b::/96) or…

Affected: Packagist: phanan/koel

## Summary

Koel's outbound-URL guard `App\Helpers\Network::isPublicHost()` classifies an IP as "public" using PHP's `filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE)`. That flag set does **not** recognise IPv6 transition-address forms that embed a private/loopback/link-local IPv4: NAT64 well-known prefix `64:ff9b::/96` (RFC 6052) and 6to4 `2002::/16` (RFC 3056). An address such as `64:ff9b::7f00:1` (= `127.0.0.1`), `64:ff9b::a9fe:a9fe` (= `169.254.169.254`, the cloud metadata endpoint), or `2002:a00:1::` (= `10.0.0.1`) is reported as a public address, so the guard returns `true` and Koel proceeds to fetch the URL.

The guard is the only SSRF defense in front of `App\Values\Podcast\EpisodePlayable::createForEpisode()`, which downloads a podcast episode with `Http::sink($file)->get($url)` and streams the response body back to the requesting user. Because an attacker fully controls the `<enclosure url>` of any RSS feed they host (and any authenticated user can subscribe to a feed), they can publish an enclosure whose hostname has an `AAAA` record that is a NAT64/6to4 wrapper of an internal IP. On hosts with NAT64 or 6to4/dual-stack routing (the standard configuration on IPv6-only AWS/GCP subnets and 6to4-relayed networks), the kernel routes the wrapper to the embedded IPv4, and Koel performs a full-read SSRF against the internal endpoint — returning the response body to the attacker.

This is a server-side request forgery with full resp…

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EUVD-2026-358647

fkie_cve-2026-54494

GHSA-rjg7-r26h-cfp2 — Koel: Full-read SSRF via podcast enclosure URL: isPublicHost() filter_var guard does not reject NAT64 (64:ff9b::/96) or…