Marcus & Millichap data breach: 1.8M accounts exposed
Severity: medium · Patch status: no-fix-needed · Since 2026-05-03
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". Exposed data: email addresses, employers, job titles, names, phone numbers, physical addresses. The breach dates from Apr 12, 2026; Have I Been Pwned loaded it on May 3, 2026.
What to do
- If you had a Marcus & Millichap account, change its password and the password of any other account that reused it.
- Turn on multi-factor authentication wherever it is offered.
- Check whether your addresses are in this breach at https://haveibeenpwned.com.
- Expect targeted phishing that quotes the leaked details; verify any unexpected contact out of band.
Sources
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