Cal. Rev. & Tax. Code § 19542

Except as otherwise provided in this article and as required to administer Section 19005, it is a misdemeanor for the Franchise Tax Board or any member thereof, or any deputy, agent, clerk, or other officer or employee of the state, including its political subdivisions, or a jury commissioner, or any former officer or employee or other individual, who in the course of their employment or duty has or had access to returns, reports, or documents required to be filed under this part, to disclose or make known in any manner information as to the amount of income or any particulars, including the business affairs of a corporation, set forth or disclosed therein.