RUSTSEC-2022-0004: 
Rust vulnerability analysis and mitigation

When parsing JSON using json::Json::from_str, there is no limit to the depth of the stack, therefore deeply nested objects can cause a stack overflow, which aborts the process. Example code that triggers the vulnerability is

fn main() {
    let _ = rustc_serialize::json::Json::from_str(&"[0,[".repeat(10000));
}

serde is recommended as a replacement to rustc_serialize.