https://foundation.mozilla.org/fr/about/public-records/
Conveniently for them and curiously, they are only publishing the "consolidated" statements for the Moz Foundation.
But, for example, it looks like that the individual statements for the Mozilla Corp are never published or disclosed. That is very annoying as it is the main "entity" of the organization.
There is also no details about the split of costs and revenues associated with each main projects / services products / groups that are worked on for a given year.
So, for example, no one can have a clear idea of how much money is spent on dev, marketing or administration of Firefox versus Pocket versus VPN versus charities versus fellowships, etc...
If you look at the content of the limited financial documents, you can even have the impression that the foundation has no interest for the development of Firefox itself, and that they are just interested by it as a cash cow that generates (with the search deals) huge funds to give to whatever charities that Mozilla leaders are interested in.