Is there a patch available for CVE-2026-49246?

Yes, a patch is available for CVE-2026-49246. Update the affected software to the latest version immediately.

Jellyfin CVE-2026-49246

Q: What is the CVSS score of CVE-2026-49246?

CVE-2026-49246 has a CVSS 4.0 base score of 1.7 (Low). CVSS 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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. EPSS exploitation probability: 0.3%.

EUVD-2026-39029 LOW

Path Traversal (CWE-22)

2026-06-24 GitHub_M

Path Traversal Jellyfin

1.7

CVSS 4.0 · Vendor: GitHub_M

Severity by source

Vendor (GitHub_M) PRIMARY

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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

vuln.today AI

3.1 LOW

AC:H for craft-and-deliver MKV requirement; UI:R because victim must actively play the file; I:L for bounded arbitrary file write; no confidentiality or availability impact.

3.1 AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N

4.0 AV:N/AC:H/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

Primary rating from Vendor (GitHub_M).

CVSS VectorVendor: GitHub_M

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Lifecycle Timeline

Patch available

Jun 24, 2026 - 20:03 EUVD

Analysis Generated

Jun 24, 2026 - 19:23 vuln.today

DescriptionCVE.org

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.

AnalysisAI

Path traversal in Jellyfin prior to 10.11.10 enables an attacker who can place a crafted MKV file in a victim's Jellyfin library to redirect the server's MKV attachment extraction routine to arbitrary absolute filesystem paths on the host. The flaw originates in .NET's Path.Combine behavior: Jellyfin passes the unsanitized MKV filename tag directly into Path.Combine(attachmentFolder, fileName), and .NET silently ignores the base path when the second argument is rooted, enabling full path override. Exploitation is triggered automatically whenever any Jellyfin client plays the affected file with subtitle burning enabled, which is the default behavior. No public exploit has been identified at time of analysis, and the CVSS 4.0 score of 1.7 reflects high complexity and low integrity-only impact.

Technical ContextAI

Jellyfin (CPE: cpe:2.3:a:jellyfin:jellyfin:*:*:*:*:*:*:*:*) is an open-source, self-hosted media server written in .NET. MKV (Matroska) containers support embedded attachments - such as subtitle fonts or images - each of which carries a filename tag. Jellyfin's PathManager.GetAttachmentPath method constructs the extraction destination by calling Path.Combine(attachmentFolder, fileName) using the MKV-embedded filename tag verbatim. CWE-22 (Improper Limitation of a Pathname to a Restricted Directory) applies directly: .NET's Path.Combine does not normalize '..' sequences and, critically, treats a rooted second argument (e.g., '/etc/cron.d/evil') as overriding the entire base path, discarding attachmentFolder entirely. A threat actor who forges the filename tag in an MKV attachment can therefore direct the extraction to any path the Jellyfin process has write access to on the server filesystem. The attack surface is activated when subtitle burn-in is attempted during playback, a behavior enabled by default in Jellyfin clients.

RemediationAI

Upgrade Jellyfin to version 10.11.10, which introduces path sanitization in PathManager.GetAttachmentPath to reject rooted second arguments and normalize '..' sequences before calling Path.Combine. The vendor advisory is available at https://github.com/jellyfin/jellyfin/security/advisories/GHSA-f47c-m7gr-q92j. For deployments that cannot immediately upgrade, a compensating control is to disable subtitle burn-in in Jellyfin client settings, which prevents MKV attachment extraction from being triggered during playback - note this will degrade subtitle rendering for affected content. Additionally, running the Jellyfin process under a restricted service account with minimal filesystem write permissions limits the blast radius of a successful path traversal to directories that account can access. Neither workaround removes the underlying flaw; patching to 10.11.10 is the only complete fix.