508 email addresses leaked from Yokohama facility booking system
SpilloverSpillover from the Arara incident · View original incident →Unauthorised 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 organisations and 65 belonging to facilities. The city was notified of the unauthorised access and service suspension on 28 October 2026, confirmed the scale of the leak on 9 November, and announced it on 10 November.
Key facts
- Affected organisation
- City of Yokohama
- Original incident
- Arara email service cyber-attack 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 organisations and 65 belonging to facilities
- Cause / method
- Unauthorised access to Arara
- Location
- Japan
If your data was exposed
Exposed dataEmail
- Don’t tap links in texts, calls or emails that mention this incident and offer compensation, refunds or breach checks. Check directly on the organisation’s official website or app.
Timeline
- The leak of email addresses belonging to organisations using Yokohama's facility booking system became public.
Original incident
This is spillover from the Arara incident.
Arara email service cyber-attack 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 misused the service to send up to approximately 7.13 million emails impersonating credit card companies, and the company isolated the servers and suspended its email delivery service entirely.
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 organisation’s official statements for accurate details.