CVE-2026-35031
Jellyfin: Potential RCE via subtitle upload path traversal + .strm chain
- Published
- Apr 14, 2026
- Updated
- Apr 16, 2026
- Assigning CNA
- GitHub_M
- Evidence observed
- Aug 28, 2026
Primary CVSS
nvd · CVSS 3.1
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:HLow · next 30 days
- Percentile
- 53.1%
- Model date
- Sep 21, 2026
EPSS is a statistical estimate, not a certainty or a measure of impact. Combine it with CVSS, KEV status, exposure and your environment.
Summary
Jellyfin is an open source self hosted media server. Versions prior to 10.11.7 contain a vulnerability chain in the subtitle upload endpoint (POST /Videos/{itemId}/Subtitles), where the Format field is not validated, allowing path traversal via the file extension and enabling arbitrary file write. This arbitrary file write can be chained into arbitrary file read via .strm files, database extraction, admin privilege escalation, and ultimately remote code execution as root via ld.so.preload. Exploitation requires an administrator account or a user that has been explicitly granted the "Upload Subtitles" permission. This issue has been fixed in version 10.11.7. If users are unable to upgrade immediately, they can grant non-administrator users Subtitle upload permissions to reduce attack surface.
Sources
1- CVE-2026-35031Exploit
Critical path traversal to RCE vulnerability in Jellyfin Media Server (CVSS 9.9). Includes proof-of-concept exploit, technical analysis, and detection tools.
Responsible use
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