Path Traversal in Jellyfin (CVE-2026-49246)
Summary
Path traversal in Jellyfin (CVE-2026-49246). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 10.11.10 or later.
Original description
The description as published by the source.
Jellyfin is an open source self hosted media server. Prior to 10.11.10, a specifically crafted MKV file containing forged filename tags can be leveraged to exploit missing path sanitization during playback. Jellyfin treats the MKV file name tag on MKV attachments as trusted and passes it unsanitized into Path.Combine(attachmentFolder, fileName) inside PathManager.GetAttachmentPath. Because .NET's Path.Combine neither normalises .. nor rejects a rooted second argument, a crafted MKV can redirect Jellyfin's MKV attachment extraction to any absolute path on disk. This triggers on any playback action of the affected video on a client which will attempt to burn in the subtitles by default.g This vulnerability is fixed in 10.11.10.
Source: NIST National Vulnerability Database 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-2026-49246 has been found in Jellyfin.
Risk of unauthorized operations or information disclosure.
What to do: upgrade Jellyfin to 10.11.10 or later.
If unsure, ask your IT team or search "Jellyfin CVE-2026-49246" on the vendor's site.
CVE-2026-49246 (Jellyfin) — CWE-22
Patched: 10.11.10 — 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.
Path traversal (CWE-22) exists in Jellyfin.
Check the vendor advisory for the affected versions of Jellyfin.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to 10.11.10.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'Jellyfin' . 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
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1Identify exposure identify
grep -r 'Jellyfin' . | 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
Jellyfinを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade Jellyfin to 10.11.10ステージング環境で 10.11.10 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を含めること。
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3Post-deployment verification verify
Confirm patched version is live in production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。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
References
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov