Jellyfin is a free software media system that provides media from a dedicated server to end-user devices via multiple apps. Verions prior to 10.7.3 vulnerable to unauthenticated Server-Side Request Forgery (SSRF) attacks via the imageUrl parameter. This issue potentially exposes both internal and external HTTP servers or other resources available via HTTP `GET` that are visible from the Jellyfin server. The vulnerability is patched in version 10.7.3. As a workaround, disable external access to the API endpoints `/Items/*/RemoteImages/Download`, `/Items/RemoteSearch/Image` and `/Images/Remote` via reverse proxy, or limit to known-friendly IPs.
Use CWE-918, Jellyfin vendor hub and Jellyfin product page to widen CVE-2021-29490 into its surrounding weakness, vendor, and product context.
Compare it with CVE-2026-31852, CVE-2026-35031 and CVE-2026-35033 for nearby disclosures in the same product family.