Science & Tech · Cybersecurity · 1 hr ago
Hack of emergency alert system may expose data from 3.13 million email addresses
A cyberattack hit a provider of emergency alert systems used by local governments across Japan.
The provider, Arcadia, said information may have been exposed from parts of its SpeeCAN RAIDEN service, which is used by about 700 municipalities.
Up to 3.136 million email addresses may be affected, along with phone and fax numbers, names and saved message text.
Municipalities including Saitama City, Yokosuka City and Oita Prefecture have announced possible data exposure.
Some residents have already received suspicious emails claiming to be from a credit card company.
Local governments have temporarily stopped some affected services while the provider blocks access and investigates.
The incident matters because the systems carry emergency and other public information, and exposed contact details could be misused.
The provider has not said when the suspended services will resume.
An unauthorized access incident may have exposed data held by a disaster-alert email system used by municipalities across Japan.
The system, SpeeCAN RAIDEN, is provided by Arcadia, based in Minoh, Osaka Prefecture.
Arcadia said up to about 3.136 million email addresses may have been exposed, along with phone and fax numbers, names and saved message text.
Some people in affected municipalities have already received suspicious emails posing as messages from credit card companies.
Arcadia and municipalities suspended some system services and blocked the IP address linked to the access.
- Who
- Arcadia, the provider of the SpeeCAN RAIDEN system, and municipalities that use it.
- What
- Unauthorized access may have exposed email addresses and other stored information.
- When
- Arcadia detected suspicious activity on October 11, 2026; municipalities announced the incident on October 13.
- Where
- The affected service environments were used by municipalities across Japan.
- Why
- The reason for the unauthorized access is not stated.
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Arcadia said it detected suspicious activity.
Arcadia took emergency measures to block the route used to enter the system.
Arcadia identified the entry route, began suspending some SpeeCAN RAIDEN environments from 11 a.m. and blocked the source IP address; municipalities announced possible data exposure.
- Potentially exposed email addresses
- Up to about 3,136,000
- Potentially exposed phone numbers
- Up to about 105,000
- Potentially exposed fax numbers
- Up to about 15,000
- System provider
- Arcadia, Minoh, Osaka Prefecture
- Service
- SpeeCAN RAIDEN