CVE-2026-49247
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.
How to fix
Sources list no fixed version or patch link for this vulnerability.
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| jellyfin jellyfin | >= 10.9.0, < 10.11.10 | — |
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