Fabien Pontencier has made an official announcement about a move to make the PHP Security Database the Symfony project started over a year ago. In the announcement he talks about the move to (hopefully) make it more widely adopted - pulling it out from under the Symfony namespace and into the FriendsOfPHP organization.

A year and a half ago, I was very proud to announce a new initiative to create a database of known security vulnerabilities for projects using Composer. It has been a great success so far; many people extended the database with their own advisories. As of today, we have vulnerabilities for Doctrine, DomPdf, Laravel, SabreDav, Swiftmailer, Twig, Yii, Zend Framework, and of course Symfony (we also have entries for some Symfony bundles like UserBundle, RestBundle, and JsTranslationBundle.)

[...] Today, I've decided to get one step further and to clarify my intent with this database: I don't want the database to be controlled by me or SensioLabs, I want to help people find libraries they must upgrade now. That's the reason why I've added a LICENSE for the database, which is now into the public domain.

The database has already been moved over to the FriendsOfSymfony organization and is still functioning with the SensioLabs security checker. You can find more on the database and its contents in this GitHub project.