Jellyfin is an open source self hosted media server. From 10.9.0 until 10.11.10, the POST /ClientLog/Document endpoint accepts the Authorization header's Client and Version fields and uses them unsanitized as components of the on-disk filename when persisting client-uploaded log documents. As a result, any authenticated non-admin user can include ../ sequences in the Client field to cause Jellyfin to write attacker-controlled content to arbitrary paths reachable by the Jellyfin service user, with a forced .log suffix. This vulnerability is fixed in 10.11.10.
History

Thu, 25 Jun 2026 17:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Thu, 25 Jun 2026 06:30:00 +0000

Type Values Removed Values Added
First Time appeared Jellyfin
Jellyfin jellyfin
Vendors & Products Jellyfin
Jellyfin jellyfin

Wed, 24 Jun 2026 18:45:00 +0000

Type Values Removed Values Added
Description Jellyfin is an open source self hosted media server. From 10.9.0 until 10.11.10, the POST /ClientLog/Document endpoint accepts the Authorization header's Client and Version fields and uses them unsanitized as components of the on-disk filename when persisting client-uploaded log documents. As a result, any authenticated non-admin user can include ../ sequences in the Client field to cause Jellyfin to write attacker-controlled content to arbitrary paths reachable by the Jellyfin service user, with a forced .log suffix. This vulnerability is fixed in 10.11.10.
Title Jellyfin: Potential Authenticated path traversal in /ClientLog/Document
Weaknesses CWE-22
References
Metrics cvssV3_1

{'score': 8.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-06-24T18:18:46.137Z

Updated: 2026-06-26T03:55:58.837Z

Reserved: 2026-05-28T14:33:01.178Z

Link: CVE-2026-49247

cve-icon Vulnrichment

Updated: 2026-06-25T17:09:54.877Z

cve-icon NVD

No data.

cve-icon Redhat

No data.