Monteroza data breach
Monteroza announced a data breach on Nov 4, 2026 affecting about 625,429 email addresses, exposing email addresses and dates of birth. It happened through a vendor (Arara (email delivery service)). No settlement or compensation has been announced.
Was I affected?
Members of Monteroza's email newsletter.
| Announced | Nov 4, 2026 |
|---|---|
| When it happened | Attack on a web server vulnerability in part of email vendor Arara's systems, found November 2, 2026 |
| Country | Japan |
| Email addresses exposed | 625,429 |
| Data exposed | Email addresses, Dates of birth and Other details |
| Through a vendor | Arara (email delivery service) |
| Status | Confirmed by the company or a regulator filing |
What happened
Monteroza, the Japanese izakaya pub chain operator, said on November 4, 2026 that 625,429 email addresses of its newsletter members may have leaked after an outsider broke into the email delivery service of Arara, its email contractor. For 31,333 of them, optional details such as date of birth, gender, prefecture, favorite restaurant brand and purpose of use may also have been taken. Monteroza does not hold names, home addresses or card numbers. It has stopped new sign-ups and newsletter emails.
What should I do?
- Be wary of emails or texts claiming to come from Monteroza, one of its restaurant brands or Arara, and don't open their links or attachments or reply.
- Don't enter your ID, password or personal details for messages about coupons or bookings.
- Consider tightening spam filtering on the address you registered if scam emails increase.
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