CVE-2026-35031
9.9 · CRITICALOverview
CVE-2026-35031 is a critical-severity vulnerability affecting jellyfin jellyfin. It was published on April 14, 2026 and has a CVSS 3.1 base score of 9.9 (CRITICAL).
This vulnerability has a CVSS 3.1 base score of 9.9, rated CRITICAL. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
Technical Description
Jellyfin is an open source self hosted media server. Versions prior to 10.11.7 contain a vulnerability chain in the subtitle upload endpoint (POST /Videos/{itemId}/Subtitles), where the Format field is not validated, allowing path traversal via the file extension and enabling arbitrary file write. This arbitrary file write can be chained into arbitrary file read via .strm files, database extraction, admin privilege escalation, and ultimately remote code execution as root via ld.so.preload. Exploitation requires an administrator account or a user that has been explicitly granted the "Upload Subtitles" permission. This issue has been fixed in version 10.11.7. If users are unable to upgrade immediately, they can grant non-administrator users Subtitle upload permissions to reduce attack surface.
Remediation
Check the references section for vendor advisories and patches from jellyfin. Update jellyfin to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| jellyfin | jellyfin | >= 0, < 10.11.7 | Affected |
Frequently Asked Questions
What is CVE-2026-35031?
CVE-2026-35031 is a critical-severity vulnerability affecting jellyfin jellyfin. It was published on April 14, 2026 and has a CVSS 3.1 base score of 9.9 (CRITICAL).
How severe is CVE-2026-35031?
This vulnerability has a CVSS 3.1 base score of 9.9, rated CRITICAL. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
How do I fix or remediate CVE-2026-35031?
Check the references section for vendor advisories and patches from jellyfin. Update jellyfin to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-35031?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-35031 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
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