CVE-2026-49220: Jellyfin: Potential XSS in user management
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.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Jellyfinto a version that resolves this vulnerability.Fixed in 10.11.9
Event History
Frequently Asked Questions
What is the severity of CVE-2026-49220?
CVE-2026-49220 has a medium severity rating of 5.7.
How do I fix CVE-2026-49220?
To fix CVE-2026-49220, upgrade to Jellyfin version 10.11.9 or later.
What type of vulnerability is CVE-2026-49220?
CVE-2026-49220 is a potential Cross-Site Scripting (XSS) vulnerability.
Who is affected by CVE-2026-49220?
CVE-2026-49220 affects Jellyfin users, specifically non-privileged users who can target logged-in Administrative users.
What potential issues can arise from CVE-2026-49220?
CVE-2026-49220 could allow non-privileged users to execute arbitrary Javascript in the context of a logged-in Administrative user, leading to various security issues.