There is no such thing as a AAA mortgage. AAA is a rating for bonds and other fixed income securities.

However, these bonds would be valueless if any of the securities that made them up defaulted.

This is not how a CDO works.

They sold the packaged bonds a AAA-rated securities without disclosing the likelihood that they would default.

Why don't you show us the CDO prospectus you allege doesn't do this? Once you produce it, I'll show you the exact (mandatory) table where it's done.

https://en.wikipedia.org/wiki/Collateralized_debt_obligation

Your comment is the financial equivalent of "The NSA is hacking my pixels in order to break the rot13 encryption." The words kind of suggest computing/finance, but anyone who knows what the words mean recognizes that the content is nonsense.