The Office of the Australian Information Commissioner (OAIC) received 667 notifications under the Notifiable Data Breaches scheme in the first half of 2026. That is only five more than the previous six months.
The size of breaches is what changed. Breaches affecting more than 1,000,000 people rose from four to 11.
Top sectors by notifications
| Sector | Notifications |
|---|---|
| Health providers | 149 |
| Education | 85 |
| Business and professional associations | 79 |
| Finance | 51 |
| Personal services | 51 |
Causes
The OAIC said malicious or criminal activity drove most breaches. In health alone there were 72 malicious cyber attacks.
