Mixed marriages and disparity of cult
According to the law in force in the Latin Church, a mixed marriage needs for liceity the express permission of ecclesiastical authority. In case of disparity of cult an express dispensation from this impediment is required for the validity of the marriage. This permission or dispensation presupposes that both parties know and do not exclude the essential ends and properties of marriage and the obligations assumed by the Catholic party concerning the baptism and education of the children in the Catholic Church.
Source: Catechism of the Catholic Church (Vatican.va)