Section 6156 Of Article 4. Directors From California Financial Code >> Division 2. >> Chapter 3. >> Article 4.

. (a) Any vacancy among directors, not filled by the members or stockholders, may be filled by a majority vote of the remaining directors, though less than a quorum, by electing a director to serve until the next annual meeting of the members or stockholders, at which time a director shall be elected to fill the vacancy for the unexpired term for the class of director in which the vacancy exists.
  (b) In the event of a vacancy on the board of directors from any cause, the remaining directors shall have full power and authority to continue direction of the association until the vacancy is filled.