Versions of `lodash.defaultsdeep` before 4.6.1 are vulnerable to Prototype Pollution. The function 'defaultsDeep' may allow a malicious user to modify the prototype of `Object` via `__proto__` causing the addition or modification of an existing property that will exist on all objects.
## Recommendation
Update to version 4.6.1 or later.
Versions of `lodash.defaultsdeep` before 4.6.1 are vulnerable to prototype pollution. The function `mergeWith` may allow a malicious user to modify the prototype of `Object` via `{constructor: {prototype: {...}}}` causing the addition or modification of an existing property that will exist on all objects.
## Recommendation
Update to version 4.6.1 or later.
Versions of lodash lower than 4.17.12 are vulnerable to Prototype Pollution. The function defaultsDeep could be tricked into adding or modifying properties of Object.prototype using a constructor payload.