{"id":"CVE-2026-73291","summary":"Seerr: Path traversal to RCE via /avatarproxy image cache filename from upstream ETag","details":"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.","aliases":["GHSA-mc6w-69r3-62h8"],"modified":"2026-08-15T11:31:24.255377209Z","published":"2026-08-12T14:48:21.783Z","database_specific":{"cwe_ids":["CWE-22","CWE-94"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/73xxx/CVE-2026-73291.json","cna_assigner":"GitHub_M"},"references":[{"type":"WEB","url":"https://github.com/seerr-team/seerr/releases/tag/v3.4.0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/73xxx/CVE-2026-73291.json"},{"type":"ADVISORY","url":"https://github.com/seerr-team/seerr/security/advisories/GHSA-mc6w-69r3-62h8"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-73291"},{"type":"FIX","url":"https://github.com/seerr-team/seerr/commit/f484791105bd81bd5404e01410431ee6fe5769c2"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/seerr-team/seerr","events":[{"introduced":"0"},{"fixed":"f484791105bd81bd5404e01410431ee6fe5769c2"},{"fixed":"2dbe8860179e83ed2044d5fc8ed17679ae05e5ad"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"3.4.0"}],"source":["AFFECTED_FIELD","REFERENCES"]}}],"versions":["v3.3.0","v3.2.0","v3.1.1","v3.1.0","v3.0.1","v3.0.0","v2.7.3","v2.7.2","v2.7.1","v2.7.0","v2.6.0","v2.5.2","v2.5.1","v2.5.0","v2.4.0","v2.3.0","v2.2.3","v2.2.2","v2.2.1","v2.2.0","v2.1.0","v2.0.1","v2.0.0","v1.9.2","preview-post-blacklist","preview-pre-blacklist","preview-post-fetch","preview-pre-fetch","v1.9.1","v1.9.0","v1.8.1","v1.8.0","v1.7.0","v1.6.0","v1.5.0","v1.4.1","v1.4.0","v1.3.0","v1.2.1","v1.2.0","v1.1.1","v1.1.0","v1.0.2","v1.0.1","v1.0.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-73291.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:H"}]}