CVE-2026-35031

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.

CVSS v3 9.9 CRITICAL

9.9^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.1 / Impact : 6.0

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope CHANGED

References

Link	Resource
https://github.com/jellyfin/jellyfin/releases/tag/v10.11.7	Product Release Notes
https://github.com/jellyfin/jellyfin/security/advisories/GHSA-j2hf-x4q5-47j3	Mitigation Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:jellyfin:jellyfin:*:*:*:*:*:*:*:*

History

23 Apr 2026, 17:44

Type	Values Removed	Values Added
References	~~() https://github.com/jellyfin/jellyfin/releases/tag/v10.11.7 -~~	() https://github.com/jellyfin/jellyfin/releases/tag/v10.11.7 - Product, Release Notes
References	~~() https://github.com/jellyfin/jellyfin/security/advisories/GHSA-j2hf-x4q5-47j3 -~~	() https://github.com/jellyfin/jellyfin/security/advisories/GHSA-j2hf-x4q5-47j3 - Mitigation, Vendor Advisory
First Time		Jellyfin Jellyfin jellyfin
CPE		cpe:2.3:a:jellyfin:jellyfin::::::::

14 Apr 2026, 23:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-04-14 23:16

Updated : 2026-06-17 10:39

NVD link : CVE-2026-35031

Mitre link : CVE-2026-35031

CVE.ORG link : CVE-2026-35031

JSON object : View

Products Affected

jellyfin

jellyfin

CWE

CWE-20

Improper Input Validation

CWE-22

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

CWE-187

Partial String Comparison

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