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)
EPSS: 0.003 (17.6th percentile) — read the EPSS interpretation.
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.
Affected products
- Jellyfin — versions < 10.11.7
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
- security-advisories@github.com (Product, x_refsource_MISC, Release Notes)
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.