Resource exhaustion in Jellyfin

CVE-2026-35034

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.

Vulnerability class: DoS (Denial of Service)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.004 (36.2th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 36th percentile — 36.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-35034: held from 0.003 to 0.004.

EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.002

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-35034?
CVE-2026-35034 is a medium-severity vulnerability in Jellyfin, classified under Uncontrolled Resource Consumption. CVSS score: 6.5/10. Published 2026-04-14.
How severe is CVE-2026-35034?
Medium severity. CVSS v3 base score is 6.5 out of 10.