KDDI Multi-ISP Email Credential Exposure in Japan
Case score 75
Case score is a discovery signal based on public evidence, not a guaranteed risk rating. Use it to decide what to review first, then verify important details from the linked sources.
- Total
- 75
- Main story score
- 75
- Related evidence lift
- +0 / 20
- Contributing updates
- 0
- Context updates
- 1
- Data Leak Primary impact record for credential exposure across six Japanese ISPs. main
- Incident Corroborates the same intrusion with disclosure timing, affected providers, and containment actions. context
Overview
Latest development Open development history KDDI email platform breached via zero-day on May 16 Attackers breached the KDDI email platform used by five Japanese ISPs on May 16 after exploiting a zero-day vulnerability in third-party software, exposing email addresses and passwords across the affected service providers.
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KDDI contains compromised email system and notifies Japanese authorities
On June 23 KDDI modified the email system to prevent further damage, implemented technical countermeasures at suspected compromised locations, notified the Personal Information Protection Commission and Japan’s Ministry of Internal Affairs and Communications, and urged customers of the affected email services to change their passwords.
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KDDI confirms breach affecting six Japanese ISP email services
KDDI publicly confirmed on June 23 that an unauthorized actor had gained access to the email system it provides to several Japanese ISPs, said up to 14.22 million email addresses and passwords were likely compromised, and identified STNet, KDDI Web Communications, JCOM, Chubu Telecommunications, Nifty Corporation, and Biglobe as affected providers.
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KDDI detects intrusion in email system used by Japanese ISPs
KDDI detected unauthorized access to an email system it provides to several Japanese ISPs on June 17 and assessed that the intrusion exploited a vulnerability in third-party software, putting customer email data at risk.