Node.js version 8.5.0 included a change which caused a security vulnerability in the checks on paths made by some community modules. As a result, an attacker may be able to access file system paths other than those intended.
Version 8.5.0 of Node.js is vulnerable. 4.x and 6.x versions are NOT vulnerable.
Upgrade to the latest version of Node.js. This vulnerability was fixed with the patch from September 2017.