Was your data in the Marcus & Millichap breach?

Marcus & Millichap (marcusmillichap.com) suffered a data breach in 2026 that exposed around 1,837,078 accounts. If you had an account, some of your personal data may be circulating in leaked databases. The fastest way to know is to check your own email — free, in about 30 seconds, no password required.

What happened

In April 2026, the commercial real estate brokerage firm Marcus & Millichap was named as one of multiple alleged victims of the ShinyHunters hacking and extortion group. Data alleged to have been obtained from the company was subsequently released publicly and included 1.8M unique email addresses, along with names, phone numbers and employment-related information including employer, job title and physical company address. In their disclosure notice, Marcus & Millichap advised that data which may have been accessed appeared limited to "company forms, templates, marketing materials, and general contact information".

Breach details sourced from Have I Been Pwned, the industry-standard breach database. Risk analysis by Nullivo.

What was exposed, and why it matters

Not all breaches carry the same risk — what matters is which fields leaked. Here is what the Marcus & Millichap breach exposed and what each item actually enables:

Also listed in this breach: Email addresses, Employers, Job titles, Names, Phone numbers, Physical addresses.

What to do if you were affected

These steps are ordered for this specific breach — the most urgent action given what leaked comes first.

1. Home addresses: Get your address removed from data brokers — they re-list roughly every four months, so this needs repeating.
2. Phone numbers: Move two-factor authentication off SMS to an authenticator app or passkey, and add a port-out PIN with your mobile provider.
3. Names and usernames: Search your usual username to see what else it exposes, and use distinct handles for sensitive accounts.
4. Email addresses: Treat any message referencing this service with suspicion, and never act on links in unexpected emails.
5. Check whether your own email appears in this breach — run a free scan to confirm before you spend time on the steps above.

This breach put your details on data-broker sites

Because Marcus & Millichap exposed home addresses, this is one of the breaches that feeds people-search and data-broker sites. Those sites scrape leaked databases, combine them with public records, and republish the result as a searchable profile — which is how a single breach turns into a permanent public listing. Removal works, but brokers typically re-list within about four months, so it has to be repeated.

See our broker-by-broker removal guides →

How urgent is this now?

This breach is recent, so the data is actively traded and the risk is at its highest right now.

Remember: a breach can't be "un-leaked" — once a database is out, it exists in countless copies. The goal is to make the leaked data useless: change what can be changed, lock down what can't, and remove what has been republished.

Frequently asked questions

Breaches that exposed similar data

If the Marcus & Millichap breach affected you, these breaches exposed comparable information — worth checking too, since leaked datasets are routinely combined.

• Was your data in the Betterment breach? (2026, ~1,435,174 accounts)
• Was your data in the Udemy breach? (2026, ~1,401,259 accounts)
• Was your data in the Sysco breach? (2026, ~2,691,852 accounts)
• Was your data in the Abrigo breach? (2026, ~711,099 accounts)
• Was your data in the Ameriprise breach? (2026, ~502,597 accounts)
• Was your data in the BCD Travel breach? (2026, ~396,313 accounts)

See all breaches we cover →