Chunghwa Information Security Appoints New Chairman

1. Date of Board Resolution or Change: June 30, 2026 (Minguo 115) 2. Position: Chairman 3. Former Incumbent's Name: Chen Ming-Shih 4. Former Incumbent's Background: Chairman of Chunghwa Information Security International Co., Ltd. 5. New Appointee's Name: Huang Chih-Hsiung 6. New Appointee's Background: Executive Vice President and Chief Technology Officer, Chunghwa Telecom Corporation 7. Nature of Change: New Appointment 8. Reason for Change: Elected as new Chairman during the 21st meeting of the 3rd Board of Directors 9. Effective Date of Appointment: June 30, 2026 (Minguo 115) 10. Additional Disclosures: This announcement qualifies as material information under Article 7, Paragraph 6 of the Enforcement Rules of the Securities and Exchange Act, applicable to publicly listed companies; however, no further disclosures are required. Keyword: Material Information