California Code, Corporations Code - CORP § 411

A transferee of shares for which the full agreed consideration has not been paid to the issuing corporation, who acquired them in good faith, without knowledge that they were not paid in full or to the extent stated on the certificate representing them or, in the case of uncertificated securities, on the applicable initial transaction statement, is liable only for the amount shown by the certificate or statement to be unpaid on the shares represented thereby, until the transferee transfers the shares to one who becomes liable therefor; provided that the transferor shall remain personally liable if so provided on the certificate or statement or agreed upon in writing. The liability of any holder of such shares who derives title through such a transferee and who is not a party to any fraud affecting the issue of the shares is the same as that of the transferee through whom title is derived.