If my aunt died and left me a $50,000 CD, is her husband entitled to a portion of the money?

Are you a named beneficiary of the CD? Or is this gift by a will? In the former case the proceeds of the CD is yours. In the case of the will, the provisions of the will will determine the ownership of the CD.

In Florida, your aunt's husband may be entitled to a portion of the CD proceeds, even if you are the only named beneficiary.  Florida and many other states provide an "elective share" for the surviving spouse.  This allows the spouse to "elect" to receive a portion of all the decedent's assets whether passed into the probate estate or through another means (like a named beneficiary).  In Florida, the elective share is 30% of the assets.  Exactly what the husband would receive depends on all of your aunt's property.

Louisiana has a different law system than most other states.  It is a "civil law" jurisdiction that evolved from French law while most other states are "common law" jurisdictions that evolved from English law.  You should consult a Louisiana estate attorney to advise you about the proceeds of this CD.