A weakness in yt‑dlp‑web‑ui allows an unauthenticated attacker to inject dash‑prefixed parameters into the Service.Formats JSON‑RPC method. The injected arguments are passed directly to yt‑dlp, enabling the use of options such as --load-info-json. This causes yt‑dlp to read arbitrary JSON files from the server’s filesystem, and the file contents are reflected in the RPC response. The result is an ability to read any file that the web server process can access, exposing sensitive data.

Marcopiovanello’s yt‑dlp‑web‑ui through version 4.0.0 is affected. All releases up to and including 4.0.0 are vulnerable.

The CVSS score of 6.9 indicates moderate severity. The EPSS score is unavailable, and the vulnerability is not listed in the CISA KEV catalog. Attackers can reach the vulnerable endpoint simply by sending HTTP or WebSocket requests to /rpc/http or /rpc/ws without authentication. Because the chosen files are read directly by the web server, the exploitation condition is minimal: any file readable by the server process can be disclosed. The impact could be significant if privileged data or configuration files are stored on the host.