wpscan maintains a vulnerability database at https://wpvulndb.com/

a plugin you can add to your site: https://wordpress.org/plugins/plugin-security-scanner/
It will alert you if any of your plugins have vulnerabilities. It uses the wpscan database

Then there is https://www.exploit-db.com/ which goes beyond wordpress.

And .... if you are a gluten for more there is the cve details http://www.cvedetails.com/