{"id":"CVE-2026-73291","title":"Seerr is an open-source media request and discovery manager for Jellyfin, Plex, and Emby","summary":"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 fi…","severity":"high","cvss":7.1,"cvssVector":"CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:H","cwe":["CWE-22","CWE-94"],"published":"2026-08-12","updated":"2026-09-18","sourceUpdated":"2026-09-18T20:09:01.757","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-73291","references":[{"url":"https://github.com/seerr-team/seerr/commit/f484791105bd81bd5404e01410431ee6fe5769c2","label":"security-advisories@github.com"},{"url":"https://github.com/seerr-team/seerr/releases/tag/v3.4.0","label":"security-advisories@github.com"},{"url":"https://github.com/seerr-team/seerr/security/advisories/GHSA-mc6w-69r3-62h8","label":"security-advisories@github.com"}],"tags":["nvd"],"epss":0.00273,"epssPercentile":0.19913,"ingestedAt":"2026-09-18T20:51:25.603Z","slug":"CVE-2026-73291","body":"## Overview\n\nSeerr 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":39.1,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}