We will naturally monitor all relevant vendor websites, but as we all know, the vendors aren't always open and upfront when they fix security related issues, so we need a number of other sources.

And for too long the NVD and CVE has not been up-to-speed, nor do they cover everything.

We are aware of the following open databases:
https://sec.hpi.de/vulndb/
https://vuldb.com/
https://www.securityfocus.com/bid/
https://www.kb.cert.org/vuls/
https://jvn.jp/en/jp/index.html
https://www.exploit-db.com/
http://seclists.org/fulldisclosure/

Please comment on this topic, with links to other sources you may find relevant.