Koel has SSRF through Authenticated Subsonic podcast feed URLs

Exploitation

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

CVSS

6.4 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Summary Koel's Subsonic createPodcastChannel.view endpoint accepts a user supplied podcast feed URL and fetches it server-side before applying the safe URL checks that are used for podcast episode enclosure URLs. An authenticated Subsonic API user can provide a loopback or internal URL as the feed URL and cause the Koel backend to issue a request to that address. A related redirect gap exists in the podcast stream helper: PodcastService::getStreamableUrl() validates only the original URL, then lets Guzzle follow redirects and accepts the final redirected URL without re-validating it. Impact An attacker with any valid Koel account and Subsonic API key can trigger server-side requests from the Koel host to loopback or internal network services. This can be used for blind SSRF against internal HTTP endpoints reachable by the Koel deployment. If an internal service returns valid RSS/XML or permissive CORS responses, parts of the response or final URL may be reflected back through normal…

Published by the source

15 Jul 2026, 17:31 UTC

Last modified by the source

15 Jul 2026, 17:31 UTC

Source last checked

26 Oct 2026, 14:50 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-8q6q-m837-fv64

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

# Patch Next advisory brief: GHSA-8q6q-m837-fv64

Advisory: Koel has SSRF through Authenticated Subsonic podcast feed URLs
IDs: GHSA-8q6q-m837-fv64
Record: https://patchnext.com/advisories/ghsa-8q6q-m837-fv64 (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 6.4)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: phanan/koel 9.7.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist phanan/koel: affected <= 9.6.0; fixed in 9.7.0

## 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-8q6q-m837-fv64 (GitHub-reviewed advisory GHSA-8q6q-m837-fv64 lists affected ranges: Packagist phanan/koel >=0 <=9.6.0)

Commands are suggestions: review each one before running it.