Vulnerability Description
Seerr is an open-source media request and discovery manager for Jellyfin, Plex, and Emby. Prior to version 3.4.0, Seerr's ImageProxy in server/lib/imageproxy.ts uses the upstream ETag and Content-Type response headers to build a cache filename for the unauthenticated GET /avatarproxy/:jellyfinUserId route, allowing a malicious or compromised Jellyfin or Emby server, or a man-in-the-middle attacker on a plaintext media-server connection, to supply traversal sequences that path.join and fs.writeFile normalize outside the cache directory, overwrite /app/dist/index.js or other files, and execute code as the node user after a container restart. This issue is fixed in version 3.4.0.
CVSS Score
HIGH
Related Weaknesses (CWE)
References
- https://github.com/seerr-team/seerr/commit/f484791105bd81bd5404e01410431ee6fe576
- https://github.com/seerr-team/seerr/releases/tag/v3.4.0
- https://github.com/seerr-team/seerr/security/advisories/GHSA-mc6w-69r3-62h8
FAQ
What is CVE-2026-73291?
CVE-2026-73291 is a vulnerability with a CVSS score of 7.1 (HIGH). Seerr is an open-source media request and discovery manager for Jellyfin, Plex, and Emby. Prior to version 3.4.0, Seerr's ImageProxy in server/lib/imageproxy.ts uses the upstream ETag and Content-Type...
How severe is CVE-2026-73291?
CVE-2026-73291 has been rated HIGH with a CVSS base score of 7.1/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-73291?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.