CVE-2026-49246

Jellyfin: Potential MKV attachment filename path traversal to RCE

State: Published
Severity: 1.7 Low
Published: Jun 24, 2026
Updated: Jun 25, 2026
Reserved: May 28, 2026

Description

Jellyfin is an open source self hosted media server. Prior to 10.11.10, a specifically crafted MKV file containing forged filename tags can be leveraged to exploit missing path sanitization during playback. Jellyfin treats the MKV file name tag on MKV attachments as trusted and passes it unsanitized into Path.Combine(attachmentFolder, fileName) inside PathManager.GetAttachmentPath. Because .NET's Path.Combine neither normalises .. nor rejects a rooted second argument, a crafted MKV can redirect Jellyfin's MKV attachment extraction to any absolute path on disk. This triggers on any playback action of the affected video on a client which will attempt to burn in the subtitles by default.g This vulnerability is fixed in 10.11.10.

Scores

CVSS	Score	Vector	Source
4.0	1.7 Low	CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U	GitHub_M

Weaknesses

CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Affected Products

Product	Versions
jellyfinjellyfin	< 10.11.10Affected

References

https://github.com/jellyfin/jellyfin/security/advisories/GHSA-f47c-m7gr-q92j

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