A KDDI data breach has put up to 142 million ISP email logins at risk across Japan

James Whitmore reports Data breach at Japanese telecoms operator KDDI may have exposed up to 1422 million email addresses and passwords linked to ISP mail services after attackers gained unauthorised access to a system used by six providers in Japan KDDI said it confirmed the incident on 17 June 2026 repaired the affected system the same day Source