estree-util-value-to-estree converts a JavaScript value to an ESTree expression. When generating an ESTree from a value with a property named __proto__, valueToEstree would generate an object that specifies a prototype instead. This vulnerability is fixed in 3.3.3.

Affected: npm: estree-util-value-to-estree

### Impact When generating an ESTree from a value with a property named `__proto__`, `valueToEstree` would generate an object that specifies a prototype instead.

Example:

```js import { generate } from 'astring' import { valueToEstree } from 'estree-util-value-to-estree'

const estree = valueToEstree({ ['__proto__']: {} }) const code = generate(estree) console.log(code) ```

Output:

```js { "__proto__": {} } ```

### Patches This was fixed in version [3.3.3](https://github.com/remcohaszing/estree-util-value-to-estree/releases/tag/v3.3.3).

### Workarounds If you control the input, don’t specify a property named `__proto__`. If you don’t control the output, strip any properties named `__proto__` before passing it to `valueToEstree`.