A flaw was found in Nodejs's mixin-deep prior to versions 1.3.2 and 2.0.0. The mixin-deep function could be used to add or modify properties of the Object.prototype. The highest threat from this vulnerability is to system availability.

mixin-deep node module before 1.3.1 suffers from a Modification of Assumed-Immutable Data (MAID) vulnerability, which allows 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.