Are you looking for a manuscript copy or an edited version? If you are looking into the manuscripts this is a book that seems directly relevant, although I have not personally read it Charles M. Radding & Antonio Ciaralli, The Corpus Juris Civilis in the MIddle Ages: Manuscripts and Transmission from the Sixth Century to the Juristic Revival (Brill, Leiden, 2007). From there it would be a matter of trying to track down if any of the manuscripts are still extant.

If you are looking for an edited version, there are a few I were able to turn up from the 16th century at the earliest as well as some modern English translations.