Nothing has yet been proven, Leo has proposed a solution but I dont think it has been factually verified
and from a different site showing D. Stallings disputes to the claim.Levitov proposed a pronouciation for the characters of the Voynich MS which leads to a largely pronounceable text, which he claims is in a creole mainly based on Flemish. His translation of this text deals with a Cathar cult of Isis followers, and rites related to Euthanasia. He published his results in a monograph . The linguistic aspect has been contested by Jacques Guy and the differences with the known practices of the Cathars in S.France have been analysed by Dennis Stallings.
However, genuine historical information shows that Catharism was a variant form of Christianity, and that the endura, a terminal fast at the end of life, was a very late practice in Catharism that does not resemble Levitov's account. This historical evidence contradicts Levitov's claim of decipherment of the Voynich Manuscript.