Vulnerability · Published Jun 24, 2026 · Assigned by GitHub_M

CVE-2026-49247Jellyfin: Potential Authenticated path traversal in /ClientLog/Document

High 8.8

In plain English

A high-severity path traversal in jellyfin from jellyfin. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 46% of all known vulnerabilities).

Severity (CVSS 3.1)8.8High

Exploit odds (30 days)0.5%top 53.9% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

Vendor	Product	Versions
jellyfin	jellyfin	>= 10.9.0, < 10.11.10

Weakness: CWE-22 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References

https://github.com/jellyfin/jellyfin/security/advisories/GHSA-jg92-mrxq-vv75 x_refsource_CONFIRM