What was exposed, when it happened, and which databases confirm it.
- accounts
- 373,460
- Breached
- August 5, 2026
- Last Update
- October 7, 2026
Were you caught in this breach?
Search your email, phone number or username against every record CheckLeaked indexes.
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What happened
In August 2026, data centre operator CyrusOne was the target of a ShinyHunters "pay or leak" extortion attempt. The group subsequently published data allegedly obtained from the company, which included 373k unique email addresses across records relating to users, sales leads and CyrusOne employees. The data largely consisted of corporate contact information, including names, physical addresses, phone numbers and job titles. It also included support tickets and other information related to the organisation's operations.
Compromised Info
- Email addresses
- Employers
- Job titles
- Names
- Phone numbers
- Physical addresses
- Support tickets
Attestation
Four independent databases catalog this breach and they do not always agree. Each lane below is one source’s own count.
Sources & Link Methods
- HIBP
FAQ
What was leaked in the CyrusOne breach?
The CyrusOne breach exposed: Email addresses, Employers, Job titles, Names, Phone numbers, Physical addresses, and Support tickets.
When did the CyrusOne breach happen?
The CyrusOne breach was disclosed on August 5, 2026 and affected 373,460 records.
Am I affected by the CyrusOne breach?
Search your email, phone or username at checkleaked.cc to find out whether your data appears in the CyrusOne leak.