CVE-2026-49220 Details
Description
Jellyfin is an open source self hosted media server. Prior to 10.11.9, a potential XSS attack exists in Jellyfin which can allow a non-privileged user to execute arbitrary Javascript in the context of a logged-in Administrative user, resulting in numerous potential issues. The Client header during an AuthenticateByName can contain arbitrary HTML and Javascript, which will then be executed by the Administrative user when visiting the Access tab of the user in question from within the dashboard. This vulnerability is fixed in 10.11.9.
A cross-site scripting (XSS) vulnerability has been identified in Jellyfin versions prior to 10.11.9. This issue allows a non-privileged user to execute arbitrary JavaScript in the context of a logged-in administrative user. The vulnerability arises because the 'Client' header during the 'AuthenticateByName' process can contain unfiltered HTML and JavaScript. When the administrative user accesses the 'Access' tab of the affected user in the dashboard, the injected script is executed, potentially leading to various security issues.
Users can upgrade to Jellyfin version 10.11.9 or later, where this vulnerability has been fixed. The update improves the sanitization of the 'Client' header to prevent the injection of harmful scripts.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Jun 24, 2026CISA-ADP
Assessed Jun 24, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/jellyfin/jellyfin/security/advisories/GHSA-fv79-gmhx-xh2v | [email protected] | AdvisoryRemedyVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-79 | Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| Jellyfin | < 10.11.9 (semver) |
CPE
Remediation
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Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 24, 2026 | CVE Modified | CISA-ADP |
| Jun 24, 2026 | New CVE Received | [email protected] |