CVE-2026-35031 Jellyfin: Potential RCE via subtitle upload path traversal + .strm chain
Attackers with subtitle upload permissions can exploit path traversal to write arbitrary files, leading to remote code execution and privilege escalation.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-35031?
CVE-2026-35031 is a critical path traversal vulnerability in jellyfin, published on 14 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-35031?
It affects 1 product.
Products include Jellyfin Jellyfin.
How do I fix CVE-2026-35031?
No fix has been published for CVE-2026-35031 yet. Limit exposure of the affected software until one is available.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-35031 being exploited?
There is no known exploitation of CVE-2026-35031 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Other vulnerabilities in jellyfin
- CVE-2026-31852 Jellyfin Possible Organization/Secret Compromise from dangerous CI implementation
- CVE-2026-35033 Jellyfin: Potential SSRF + Arbitrary file read via stream argument injection
- CVE-2023-30627 jellyfin-web has a stored cross-site scripting vulnerability in devices.js
- CVE-2023-30626 Jellyfin vulnerable to directory traversal and file write causing arbitrary code execution
- CVE-2022-35909 Incorrect Access Control and Cross Site Scripting in Jellyfin
Sources
Also known as GHSA-j2hf-x4q5-47j3.