CVE-2026-54493: Koel SSRF in Subsonic Internet Radio Stations

CVE-2026-54493 · Severity: high · CVSS 7.7 · Published 2026-08-19

Koel is an open-source personal music streaming service. A security flaw in its Subsonic-compatible radio feature allows an authorized user to trick the server into accessing internal network resources that are not normally accessible from the internet. This could allow an attacker to steal sensitive data from internal databases, admin panels, or cloud metadata services.

Technologies: phanan/koel (Packagist). Vendors: Packagist.

Quick answers

Is CVE-2026-54493 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-54493 being exploited in the wild.
How severe is CVE-2026-54493?
High severity, with a CVSS score of 7.7, published 19 August 2026.
Which products and versions are affected?
phanan/koel (Packagist) <= 9.6.0, ECOSYSTEM:introduced=0,fixed=9.7.0.
Is there a fix for CVE-2026-54493?
Yes. phanan/koel (Packagist): upgrade to 9.7.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-54493 attacked?
It is attacked over the network, in a web application.
Am I affected by CVE-2026-54493?
Check whether you run phanan/koel (Packagist) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • phanan/koel (Packagist): upgrade to 9.7.0 or later
    composer require phanan/koel:^9.7.0

Technical details

A validation gap exists between Koel's standard web API and its Subsonic-compatible endpoints. While the web API uses 'SafeUrl' and 'HasAudioContentType' rules to prevent SSRF, the Subsonic routes (createInternetRadioStation.view and updateInternetRadioStation.view) lack these protections. An authenticated attacker can register a radio station with a URL pointing to internal services (e.g., loopback or RFC1918 addresses). When the station is played, the 'RadioStreamProxy::openStream' method uses 'fopen' on the attacker-controlled URL and forwards the resulting stream back to the client, resulting in a full-read SSRF. This is patched in version 9.7.0.

Affected products

  • phanan koel <= 9.6.0

Identifiers

  • CVE-2026-54493
  • GHSA-6p96-cfg5-4vhp

Timeline

  • 2026-06-04: disclosed: Initial disclosure on GitHub Advisories
  • 2026-07-15: advisory: Advisory updated with CVE-2026-54493
  • 2026-07-15: patched: Fix released in version 9.7.0

References

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