MMG Fusion
HIGH RISKData breach — December 2020
In December 2020, the dental practice management service MMG Fusion was the victim of a data breach which exposed 2.6M unique email addresses. The data also included patient appointments, names, phone numbers, dates of birth, genders and physical addresses. A small number of records also included passwords stored as bcrypt hashes.
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What happened in the MMG Fusion data breach?
In December 2020, the dental practice management service MMG Fusion was the victim of a data breach which exposed 2.6M unique email addresses. The data also included patient appointments, names, phone numbers, dates of birth, genders and physical addresses. A small number of records also included passwords stored as bcrypt hashes.
The exposed data included 9 types of personal information. Because passwords were exposed, users who reused their password on other sites are at particular risk. Learn more about what a data breach means for you.
Quick answer — was MMG Fusion hacked?
Yes. MMG Fusion was breached in December 2020. The breach exposed 2,660,295 records including appointments, dates of birth, email addresses. This breach has been independently verified. If your email was involved, your data may still be at risk today. Check if you were affected.
Why was the MMG Fusion breach so dangerous?
The MMG Fusion breach exposed 2,660,295 records — that is 2.7M people whose personal data is now circulating on the dark web. The combination of appointments, dates of birth, email addresses makes this a high-risk breach that requires immediate action.
Because passwords were exposed, attackers can use credential stuffing to automatically test your MMG Fusion password against hundreds of other websites. If you reused your password anywhere, those accounts are now at risk. Read more about what happens to your data after a breach.
Don't wait to find out — check if your email was exposed in this breach now.
What data was stolen in the MMG Fusion breach?
Appointments — may be combined with other breach data to build a profile for targeted attacks
Dates of birth — used to verify identity for account takeover and fraud
Email addresses — used for phishing attacks and credential stuffing against your other accounts
Genders — may be combined with other breach data to build a profile for targeted attacks
Marital statuses — may be combined with other breach data to build a profile for targeted attacks
Names — used to build profiles and target you with personalised scams
Passwords — can be used to access your accounts directly or cracked to reveal your actual password
Phone numbers — enables SIM swapping attacks and targeted SMS phishing scams
Physical addresses — combined with other data, used for identity theft and physical fraud
Is the MMG Fusion breach still dangerous in 2026?
Yes. Stolen data from the MMG Fusion breach remains dangerous years after the incident. Research shows that over 65% of stolen credentials from older breaches have never been changed by the account holders. Attackers routinely compile data from multiple breaches to build complete profiles, and credentials from 2020 are still actively used in credential stuffing attacks today.
Personal information like email addresses, phone numbers, and dates of birth never expire. Even if you changed your MMG Fusion password, the other exposed data can be combined with information from other breaches to target you. Learn more about how long stolen data stays dangerous.
Frequently asked about the MMG Fusion breach
Approximately 2,660,295 user records were exposed in the MMG Fusion breach in December 2020.
Yes. Leaked credentials are actively used in credential stuffing attacks years after a breach. If you reused your MMG Fusion password elsewhere and haven't changed it, those accounts remain at risk today.
Enter your email in the free checker on EmailLeaked. We scan 12 billion+ breach records including the full MMG Fusion dataset and tell you instantly whether your email was exposed and what data was taken.
Change your MMG Fusion password immediately, change any other account where you used the same password, enable two-factor authentication on all important accounts, and monitor for phishing emails over the next 90 days.
Who was affected by the MMG Fusion breach?
The MMG Fusion data breach affected approximately 2,660,295 users who had accounts with the service. While not the largest breach on record, it still represents a significant number of compromised accounts in our database of 970+ known breaches.
If you ever created an account with MMG Fusion or used their services, your data may have been included in this breach. Check your email now to find out. You can also read our guide on what to do immediately after a data breach.
If your email was in the MMG Fusion breach
Change your MMG Fusion password immediately
Go to MMG Fusion and change your password right now. Use a strong, unique password that you have never used anywhere else.
Change any account sharing that password
If you used the same password on other sites, change it on every one of them. Attackers test stolen credentials on hundreds of popular sites within hours.
Enable two-factor authentication
Turn on 2FA on MMG Fusion and every important account. Even if your password is known, attackers cannot get in without the second factor.
Check your other accounts for this breach
Run a full email check to see every breach your email appears in — not just this one.
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