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

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

5.3 · 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 · score source

EPSS

• CVE-2026-54494: 0.43% estimated exploitation activity in the next 30 days; percentile 37.05 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary Koel's outbound-URL guard App\Helpers\Network::isPublicHost() classifies an IP as "public" using PHP's filtervar($ip, FILTERVALIDATEIP, FILTERFLAGNOPRIVRANGE | FILTERFLAGNORESRANGE). That flag set does not recognise IPv6 transition-address forms that embed a private/loopback/link-local IPv4: NAT64 well-known prefix 64:ff9b::/96 (RFC 6052) and 6to4 2002::/16 (RFC 3056). An address such as 64:ff9b::7f00:1 (= 127.0.0.1), 64:ff9b::a9fe:a9fe (= 169.254.169.254, the cloud metadata endpoint), or 2002:a00:1:: (= 10.0.0.1) is reported as a public address, so the guard returns true and Koel proceeds to fetch the URL. The guard is the only SSRF defense in front of App\Values\Podcast\EpisodePlayable::createForEpisode(), which downloads a podcast episode with Http::sink($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…

Published by the source

15 Jul 2026, 18:21 UTC

Last modified by the source

15 Jul 2026, 18:21 UTC

Source last checked

26 Oct 2026, 14:50 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-rjg7-r26h-cfp2

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-54494

Advisory: 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
IDs: CVE-2026-54494, GHSA-rjg7-r26h-cfp2
Record: https://patchnext.com/advisories/cve-2026-54494 (revision 1, source checked 26 Oct 2026, 14:50 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: phanan/koel 9.7.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist phanan/koel: affected <= 9.7.0; fixed in 9.7.1

## Suggested inspection (read-only)
- Packagist phanan/koel: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on phanan/koel.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-rjg7-r26h-cfp2 (GitHub-reviewed advisory GHSA-rjg7-r26h-cfp2 lists affected ranges: Packagist phanan/koel >=0 <=9.7.0)

Commands are suggestions: review each one before running it.