---
title: "Data breach at Sourcenext"
description: "Japanese software publisher Sourcenext stated in a 15 October 2026 announcement that an unauthorised party had accessed its customer account management system. The access reportedly began on 9 October 2026 through misuse of an API used to look up member data. The activity was detected on 13 October "
canonical: https://inyourgeek.com/en/fuites-de-donnees/2026-10-15-sourcenext
type: fuite-de-donnees
author: "Sébastien Soulier"
publisher: "InYourGeek"
language: en
datePublished: 2026-10-15
dateModified: 2026-10-15
---
# Sourcenext

Data breach — High

Japanese software publisher Sourcenext stated in a 15 October 2026 announcement that an unauthorised party had accessed its customer account management system. The access reportedly began on 9 October 2026 through misuse of an API used to look up member data. The activity was detected on 13 October and the access was cut off the same day. The potentially affected scope is 22,519,960 account records, and the content varies from one account to another: names, email addresses, passwords, postal addresses, phone and fax numbers, dates of birth, gender, company and job role, subscribed services, registration dates and login history. According to the company, no payment card data was stored in the affected system. On 15 October 2026, Sourcenext confirmed the incident in a statement, then said on 16 October that it had invalidated its customers' old passwords, according to press reports relaying these announcements.

Passwords paired with email addresses can be reused by a third party to attempt access to other accounts, and the full contact details allow targeted solicitation or phishing attempts.

| Fact | Value |
| --- | --- |
| Disclosed on | October 15, 2026 |
| Incident dated | October 9, 2026 |
| Sector | Digital services |
| Country | Japan |
| Cause | Undisclosed |
| Severity | High |
| Status | Confirmed |

## Exposed data

- Full name
- Email address
- Password (hashed)
- Postal address
- Phone number
- Date of birth
- Employment data
- Order history
- Connection data (IP, logs)

## What you can do

- Change that password — and everywhere you reused it. That is how a leak spreads to your other accounts.
- Turn on two-factor authentication on the affected accounts: a stolen password is then no longer enough.
- Expect phishing attempts quoting your name and this company. A message that knows your details is not legitimate for that reason.
- You can ask the organisation exactly what was exposed about you (right of access), and complain to the DPA if no answer comes within a month.

## Sources

- [Cyberattaque : le géant japonais des logiciels Sourcenext expose 22,5 millions de comptes](https://www.cyberattaque.org/cyberattaque-le-geant-japonais-des-logiciels-sourcenext-expose-225-millions-de-comptes/) — Cyberattaque.org
- [Sourcenext : fuite possible de 22,51 millions de données clients (NHK)](https://news.web.nhk/newsweb/na/nd-20261015de60043) — NHK

_Entry built from the cited sources after a corroboration check, then reviewed before publication._

---

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