Breach Database / CyrusOne
Yes — CyrusOne was breached.
- 373,460 accounts affected
- Breach occurred 2026-08-05 · cyrusone.com
- Verified entry in the Have I Been Pwned catalog
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.
What data was exposed
- Email addresses
- Employers
- Job titles
- Names
- Phone numbers
- Physical addresses
- Support tickets
What to do right now
- Be alert for smishing and SIM-swap attempts. Treat unexpected texts and "carrier" calls with suspicion; add a PIN/port-freeze with your mobile carrier.
- Watch for targeted phishing mail. A leaked home address makes postal and doorstep scams more convincing.
- Expect convincing phishing emails. Attackers use breached details to write personalized emails. Be suspicious of any message referencing this service.
- Check your other accounts on Have I Been Pwned. Your email address may appear in other breaches you don't know about yet.
- Monitor the apps you use going forward. Clearly watches the breach record for the companies behind your apps and alerts you the moment one appears.
Breach data from Have I Been Pwned. Listing here means the service appears in the public breach record — not that your personal data was affected.