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CVE-2026-54491 high CVSS 7.1

SSRF (Server-Side Request Forgery) in phanan/koel (CVE-2026-54491)

Summary

SSRF in phanan/koel (CVE-2026-54491). Confidential information can be exposed externally. Exploitable via POST /api/podcasts. Mitigation: upgrade to 9.7.1 or later.

Original description

The description as published by the source.

Summary

The fix for CVE-2026-47260 (v9.3.5) added an initial isSafeUrl() check to several fetchers (synchronizeEpisodes, getStreamableUrl, AddRadioStation, EpisodePlayable), but the redirect-target validation — the per-hop Guzzle on_redirect callback added in follow-up commit be1e867 — was applied to only one path, EpisodePlayable. Every other server-side fetcher therefore has only the initial check, which an HTTP 302 redirect to an internal address bypasses, or no check at all. DNS rebinding (validation and connection resolve DNS separately, with no IP pinning) bypasses the initial check on every path.

An authenticated, non-admin user can thus cause the Koel server to issue requests to arbitrary internal / cloud-metadata endpoints (SSRF) by supplying a URL on an attacker-controlled host that 302-redirects to an internal address.

Note: commit be1e867 shows the redirect-based SSRF vector was recognised, but the redirect defense was applied to a single call site rather than generalised — so the class survives in the sibling paths below.

Details — Root cause

App\Helpers\Network::isPublicHost() / isSafeUrl() perform a point-in-time host check with no pinning of the resolved IP, and per-redirect-hop re-validation exists only in App\Values\Podcast\EpisodePlayable (the on_redirect callback from commit be1e867). Consequently every other fetcher is exposed to (1) redirect SSRF — initial URL passes `…

Source: GitHub Security Advisories (Global) NVD GitHub Advisory

Auto-generated summary

Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.

A vulnerability tracked as CVE-2026-54491 has been found in phanan/koel.
Attackers can target a specific entry point like POST /api/podcasts over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 7.1/10.
What to do: upgrade phanan/koel to 9.7.1 or later.
If unsure, ask your IT team or search "phanan/koel CVE-2026-54491" on the vendor's site.

CVE-2026-54491 (phanan/koel) — CWE-918 / CVSS v3 7.1
Attack vector: remote (network-reachable) / no user interaction
Attack surface: POST /api/podcasts / synchronizeEpisodes / getStreamableUrl / AddRadioStation
Patched: 9.7.1 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.

❓ What is the problem

SSRF (CWE-918) exists in phanan/koel. Attackers reach the vulnerable code path via POST /api/podcasts.

📍 Affected scope

Check the vendor advisory for the affected versions of phanan/koel. Attack surface: POST /api/podcasts / synchronizeEpisodes / getStreamableUrl / AddRadioStation.

🔥 Severity

Severity: High (CVSS 7.1/10). Confidential information can be exposed externally.

🔧 How to fix

Update to 9.7.1.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual POST /api/podcasts requests with malformed payloads or SQL meta-characters. Run grep -r 'phanan/koel' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

  1. 1
    Identify exposure identify 
    grep -r 'phanan/koel' . | grep -v node_modules

    リポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で phanan/koel を grep し、稼働しているサービス・バージョンを把握する。

  2. 2
    Hunt for indicators of compromise detect 
    grep 'POST /api/podcasts' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'

    アクセスログで POST /api/podcasts への異常なリクエスト (不正な認証ヘッダ・SQLメタ文字)を過去 30〜90日分捜索。WAF/SIEM があれば該当パスのアラート発火履歴を確認。

  3. 3
    Apply patch patch 
    Upgrade phanan/koel to 9.7.1

    ステージング環境で 9.7.1 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスと、Step 2 で見つけた異常検知の続報チェックを含めること。

  4. 4
    Post-deployment verification verify 
    Replay attack against POST /api/podcasts on staging to confirm patch closes the vector

    パッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番では Step 2 と同じログクエリでアラート再発が無いか継続監視。

Affected packages

composer phanan/koel
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"9.7.1"}]}]
Packagist phanan/koel
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"9.7.1"}]}]

References

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