Quick answers
- Is CVE-2026-35034 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-35034 being exploited in the wild.
- How severe is CVE-2026-35034?
- Medium severity, with a CVSS score of 6.5, published 14 April 2026.
- Which products and versions are affected?
- Jellyfin < 10.11.7.
- Is there a fix for CVE-2026-35034?
- A patch was published on 2026-03-31: Version 10.11.7 released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-35034 attacked?
- It is attacked over the network, in a network appliance.
- Am I affected by CVE-2026-35034?
- Check whether you run Jellyfin at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
A denial of service (DoS) vulnerability exists in Jellyfin's SyncPlay group creation endpoint (POST /SyncPlay/New). The root cause is an incorrect sanitizer that fails to limit the size of group names, leading to uncontrolled resource consumption (CWE-400). An authenticated attacker can send large payloads with arbitrary group IDs to exhaust server memory, potentially causing an Out-of-Memory (OOM) crash or locking the endpoint for legitimate users. This vulnerability is reachable over the network but requires 'Low' privileges (an authenticated account). The issue is resolved in version 10.11.7 by implementing strict size limits on the affected API endpoint.
Affected products
- Jellyfin Jellyfin < 10.11.7
Timeline
- 2026-03-31: patched: Version 10.11.7 released
- 2026-04-14: advisory: GitHub Security Advisory published
- 2026-04-14: disclosed