In his latest post Fabien Potencier introduces a new effort to help PHP developers using Composer for their dependencies find potential security issues automatically - the security.sensiolabs.com site.

I want to provide a simple and efficient way to check for vulnerabilities in a project and I want to serve more than just the Symfony community. That's why I'm really proud to announce a new SensioLabs initiative: a simple way to check if your project depends on third-party libraries with known security issues. The website explains how it works in details (https://security.sensiolabs.org/), but basically, this initiative gives you several ways to check for security issues in your project dependencies based on the information contained in you composer.lock file (you are using Composer to manage your dependencies, right?)

Composer users can upload their "composer.lock" file and the system will evaluate it against the vulnerabilities it knows about and return any issues it might find. The current database is hosted on github and can be added to by anyone using a pull request. Additionally, you can install the command-line version if you want to do checks locally.