We have an internal wiki with several namespaces which in turn have different access permissions set. Does CirrusSearch actively prevent leakage of content of pages a user has no access to?
Topic on Extension talk:CirrusSearch
I don't think so because to my knowledge there are no such support in MW out of the box, see Manual:Preventing_access#Restrict_viewing_of_certain_specific_pages. Are you using a dedicated extension for this?