🛡️ CVE-2026-49247

🟠 CVSS 8.8 — High ✅ No Known Exploit CWE-22 NVD
8.8
CVSS Score
0 Low4 Medium7 High9 Critical10

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 this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity high, availability high.

Weakness class

CVE-2026-49247 is classified as CWE-22: Path Traversal. A file path built from user input is not confined to the intended directory, letting an attacker reach files elsewhere on the filesystem.

Affected software

CVE-2026-49247 is recorded against 1 package.

  • unknown

Timeline and source

Published on 24 June 2026 and last revised on 26 June 2026. No public exploit is currently recorded for this entry. Record sourced from NVD.

References

github.com

Details

Severity HIGH
CVSS Score 8.8
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE CWE-22
Public Exploit ✅ No
Source NVD
Published 2026-06-24
Updated 2026-08-11
Modified 2026-06-26
Fix URL N/A

Affected Packages

Software From version Fixed in
unknown — —

Similar Threats

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