CVE-2026-35034
MediumCVSS 6.5Exploitation Probability (EPSS)
Low risk18th percentile - higher than 18% of all known CVEs
Summary
Jellyfin before version 10.11.7 contains a denial of service vulnerability in the SyncPlay group creation endpoint. An authenticated user can create groups with unlimited name sizes, leading to endpoint lockout and increased memory usage, potentially causing an out-of-memory crash.
Risk Assessment
An attacker can prevent other clients from joining SyncPlay groups and crash the Jellyfin server, disrupting service availability.
Recommendation
Immediately upgrade Jellyfin to version 10.11.7 or later.
Original NVD description (English source)
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.