Read the docs
TI-2026-27234 Aliases CVE-2026-35031

Jellyfin: Potential RCE via subtitle upload path traversal + .strm chain

Priority MEDIUM 44CWE-187Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA.

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00753 55th percentileScored 2026-11-07
Fix Fixed jellyfin (jellyfin): 10.11.7

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
jellyfinjellyfinbefore 10.11.710.11.7Patch availableCNA
  • jellyfin Vendorjellyfin Affected before 10.11.7 Fixed in 10.11.7 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:jellyfin:jellyfin:*:*:*:*:*:*:*:*before 10.11.7Vulnerablejellyfin
  • cpe:2.3:a:jellyfin:jellyfin:*:*:*:*:*:*:*:* Versions before 10.11.7 Vulnerable ·jellyfin

Remediation

  • Fix · CNA jellyfin (jellyfin) Fixed in 10.11.7

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-35031

References

Advisory 1

Other 1

  • TI-2021-04500 Unauthenticated Arbitrary File Access in Jellyfin CVSS 3.1HIGH 7.7
  • TI-2023-26761 Argument Injection in FFmpeg codec parameters in Jellyfin CVSS 3.1HIGH 8.8
  • TI-2021-10203 Unauthenticated GET requests through Remote Image endpoints CVSS 3.1MEDIUM 5.8
  • TI-2023-09464 In Jellyfin 10.8.x through 10.8.3, the name of a playlist is vulnerable to stored XSS. CVSS 3.1MEDIUM 5.4
  • TI-2023-09463 In Jellyfin 10.8.x through 10.8.3, the name of a collection is vulnerable to stored XSS. CVSS 3.1MEDIUM 5.4
  • TI-2026-24405 Jellyfin Possible Organization/Secret Compromise from dangerous CI implementation CVSS 3.1CRITICAL 10.0
See all 18 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences