Prosper data breach: 17.6M accounts exposed
Severity: medium · Patch status: no-fix-needed · Since 2025-10-16
In September 2025, Prosper announced that it had detected unauthorised access to their systems, which resulted in the exposure of customer and applicant information. The data breach impacted 17.6M unique email addresses, along with other customer information, including US Social Security numbers. Prosper advised that they did not find any evidence of unauthorised access to customer accounts and funds, and that their customer-facing operations were uninterrupted. Further information about the incident is contained in Prosper's FAQs. Exposed data: browser user agent details, credit status information, dates of birth, email addresses, employment statuses, government issued ids, income levels, ip addresses, names, physical addresses. The breach dates from Sep 1, 2025; Have I Been Pwned loaded it on Oct 16, 2025.
What to do
- If you had a Prosper 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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