Technically schools are accredited, not curricula. Also accreditation is only as good as the reputation of the accreditation agency. IE there is one private school accreditation agency whose only rule is that the "school" have a physical address in the US.
Using a curriculum from a school that is accredited only matters if you are using the umbrella school. Just using the curriculum without the instruction/guidance of the teachers doesn’t usually help your child at all.