Summary of Customer Complaints in 2015 re: Unauthorized Release of CPNI

Five9, Inc.

In July 2015, the company received a customer inquiry concerning an alleged social

engineering attempt which could have provided unauthorized access to CPNI. Five9 investigated this

matter and determined that Five9 had properly followed internal procedures outlined in the companys

CPNI Compliance Manual with respect to the alleged attempt. Further, Five9 reported this matter to the

U.S. Secret Service and Federal Bureau of Investigation via the Commissions Data Breach Reporting

Portal in a timely manner as required by section 64.2011 of the Commissions rules. The reference

number for this report filed on July 7, 2015, was 2015-25057. Five9 will maintain a record of its

investigation for at least three (3) years from the date the report was filed via the Commissions Data

Breach Reporting Portal.