class-transformer before 0.3.1 allow attackers to perform Prototype Pollution. The classToPlainFromExist function could be tricked into adding or modifying properties of Object.prototype using a __proto__ payload.

Affected: npm: class-transformer

class-transformer through 0.2.3 is vulnerable to Prototype Pollution. The 'classToPlainFromExist' function could be tricked into adding or modifying properties of 'Object.prototype' using a '__proto__' payload.