Like any good OpenSource project the MySQL Bugs website is open for anyone to search through. This ofcourse doesn't include the security bugs.
There is a second collection of bugs in the My Oracle Support and these bugs are only accesseble by customers with a support contract. Even when I have access to MOS I still prefer to use the community bugs site. For service requests etc. I would use MOS.
The openness of the bugs database is one of the topic the IOUG MySQL Council discusses with Oracle.
The bugs database has more to offer than just information about initial bugs:
- Bugs Statistics: This has a big matrix