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CWE-88Weakness · CWE-88

CVE-2026-48793

HIGH · 8.8 CVSS v3.1 Published 2026-06-24
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
94/100
Remediation priority · Urgent
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Command injection vulnerability in Jellyfin's subtitle conversion feature where subtitle filenames are passed to FFmpeg command-line arguments without proper path normalization, allowing injection of arbitrary FFmpeg arguments via specially crafted filenames containing double-quote characters.

MitigationUpgrade to Jellyfin 10.11.10 or later to apply the fix; additionally restrict or monitor file uploads to media library directories to prevent attackers from placing malicious subtitle files.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Determine installed Jellyfin version
    Access the Jellyfin dashboard, then navigate to Dashboard > General (or check via command line using 'jellyfin --version' or checking the installed package). Compare the version number to the fixed version 10.11.10 - versions below this are affected.
    Affected if The installed Jellyfin version is 10.11.9 or earlier (any version before 10.11.10).
  2. Verify subtitle conversion feature is in use
    Check if subtitle extraction or conversion is enabled in Jellyfin (Dashboard > Playback > Transcoding settings). Look for subtitle-related transcoding options that trigger FFmpeg calls.
    Affected if Subtitle conversion/extraction features are enabled and used, as the vulnerability requires FFmpeg to be invoked with subtitle filenames.
  3. Inspect subtitle file names in media directories
    Scan media library directories for subtitle files (common extensions: .srt, .ass, .ssa, .sub, .vtt) that contain double-quote characters (") or other shell metacharacters in their filenames. Use commands like 'find /path/to/media -name "*\"*"' to search for files with quotes.
    Affected if Subtitle files with filenames containing double-quote characters (or sequences suggesting argument injection) exist in accessible media directories.
  4. Review FFmpeg command execution logs
    Examine Jellyfin server logs (typically in /var/log/jellyfin or the log directory configured in Jellyfin) for FFmpeg invocations involving subtitles. Look for any unusual argument patterns or unexpected output in the log entries.
    Affected if Log entries show FFmpeg commands where subtitle filenames appear to have injected additional arguments (visible as unexpected parameters in the command string).

You are affected if running any Jellyfin version before 10.11.10 with subtitle conversion features enabled and subtitle files accessible to the Jellyfin service.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade to Jellyfin 10.11.10 or later to apply the fix; additionally restrict or monitor file uploads to media library directories to prevent attackers from placing malicious subtitle files.

Recommended fix High confidence

10.11.10

  1. 1. Back up your Jellyfin configuration, data directories, and any custom settings before upgrading.
  2. 2. Check your current Jellyfin version by accessing the dashboard or running `docker ps` (for Docker deployments) or checking the service version.
  3. 3. For Docker deployments: Stop the container, pull the new image with tag `10.11.10` (e.g., `docker pull jellyfin/jellyfin:10.11.10`), then recreate the container with the same configuration.
  4. 4. For native Linux installations: Update your package manager repository and upgrade Jellyfin (e.g., `sudo apt update && sudo apt install jellyfin` for APT-based systems, or check your distribution's package manager).
  5. 5. For Windows installations: Download the installer for version 10.11.10 from the official Jellyfin downloads page and run the upgrade.
  6. 6. After upgrading, verify the server starts successfully and the dashboard is accessible.
  7. 7. Test subtitle conversion functionality to confirm the vulnerability is patched.
Caveat None documented in the CVE description; minor version upgrades in Jellyfin typically do not introduce breaking changes for core functionality

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA3.0 h
16.0 hours of engineering $2,760
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-48793 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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