Vulnerability in Jellyfin (CVE-2026-48793)
Summary
Vulnerability in Jellyfin (CVE-2026-48793). Successful exploitation can lead to full system takeover. 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 potential FFmpeg argument injection vulnerability exists in the subtitle conversion code path. SubtitleEncoder.ConvertTextSubtitleToSrtInternal (SubtitleEncoder.cs, line 382) interpolates the subtitle file path into FFmpeg command-line arguments without calling EncodingUtils.NormalizePath(). On Linux, filenames can contain double-quote characters, which break the argument quoting and allow injection of arbitrary FFmpeg arguments. The vulnerability is reachable without authentication via SubtitleController.GetSubtitle, which has no [Authorize] attribute. An attacker who can place a file in a Jellyfin media library directory (shared NAS, Samba share, guest upload) can achieve arbitrary file write on the server and information disclosure. 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-2026-48793 has been found in Jellyfin.
Successful exploitation can lead to full system takeover. CVSS score: 8.8/10.
What to do: upgrade Jellyfin to 10.11.10 or later.
If unsure, ask your IT team or search "Jellyfin CVE-2026-48793" on the vendor's site.
CVE-2026-48793 (Jellyfin) — CWE-88 / CVSS v3 8.8
Attack vector: remote (network-reachable) / no user interaction
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.
A vulnerability (CWE-88) exists in Jellyfin.
Check the vendor advisory for the affected versions of Jellyfin.
Severity: High (CVSS 8.8/10). Successful exploitation can lead to full system takeover.
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