Catechism of the Catholic Church §2301 — excerpt
Autopsies can be morally permitted for legal inquests or scientific research. the free gift of organs after death is legitimate and can be meritorious. The Church permits cremation, provided that it does not demonstrate a denial of faith in the resurrection of the body.
This translation is under copyright, so only the cited words are quoted here. Follow the link for the full text. Translation: English translation of the Catechism of the Catholic Church, 2nd ed. (Libreria Editrice Vaticana), as posted at vatican.va.
Also cites: CIC, can. 1176 # 3