Vulnerability · Published Jun 24, 2026 · Assigned by GitHub_M

CVE-2026-49246Jellyfin: Potential MKV attachment filename path traversal to RCE

Low 1.7

In plain English

A low-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 0.4% (higher than 31% of all known vulnerabilities).

Severity (CVSS 4.0)1.7Low

Exploit odds (30 days)0.4%top 68.9% 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. 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.

Affected products (as reported)

Vendor	Product	Versions
jellyfin	jellyfin	< 10.11.10

Weakness: CWE-22 · Vector: 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

References

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