CVE-2026-73291 Seerr: Path traversal to RCE via /avatarproxy image cache filename from upstream ETag

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...