508 email addresses leaked from Yokohama facility booking system
SpilloverSpillover from the Arara incident · View original incident →Unauthorized access to Arara's email delivery service exposed 508 email addresses associated with Yokohama's booking system for facilities including community care plazas: 443 belonging to user organizations and 65 belonging to facilities. The city was notified of the unauthorized access and service suspension on October 28, 2026, confirmed the scale of the leak on November 9, and announced it on November 10.
Key facts
- Affected organization
- City of Yokohama
- Original incident
- Arara email service hack exposes 81.33 million email addresses
- Incident type
- Data breach
- Occurred / detected
- 2026-10-28
- Scale of damage
- 508 email addresses exposed: 443 belonging to user organizations and 65 belonging to facilities
- Cause / method
- Unauthorized access to Arara
- Location
- Japan
If your data was exposed
Exposed dataEmail
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Timeline
- The leak of email addresses belonging to organizations using Yokohama's facility booking system became public.
Original incident
This is spillover from the Arara incident.
Arara email service hack exposes 81.33 million email addresses
81.3MImpact: 81,329,467 email addresses and some customers' member information
Japan's Arara Message email delivery service was breached through a web server vulnerability, exposing email addresses and some customers' member information. Further investigation put the number of unique email addresses exposed at 81,329,467. The attacker also abused the service to send up to approximately 7.13 million emails impersonating credit card companies, and the company isolated the servers and completely suspended its email delivery service.
Related reports: 20 · last report →
1 related reports
The summary and key facts are written by AI from related reports and may contain errors. Check the original articles and the organization’s official statements for accurate details.