CVE-2026-35034 MEDIUM

CVE-2026-35034: Jellyfin: Potential Application DoS from excessively large SyncPlay group names

Vendor Jellyfin
Product jellyfin
Weakness CWE-400
Published April 14, 2026
Last update April 15, 2026

CVSS base score

6.5/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality None
Integrity None

CVSS vector

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

What the vulnerability does

01Description

Jellyfin is an open source self hosted media server. Versions prior to 10.11.7 contain a denial of service vulnerability in the SyncPlay group creation endpoint (POST /SyncPlay/New), where an authenticated user can create groups with names of unlimited size due to insufficient input validation. By sending large payloads combined with arbitrary group IDs, an attacker can lock out the endpoint for other clients attempting to join SyncPlay groups and significantly increase the memory usage of the Jellyfin process, potentially leading to an out-of-memory crash. This issue has been fixed in version 10.11.7.

Key dates

02Disclosure timeline

April 14, 2026 CVE published
April 15, 2026 Record updated