Coinbase User? Your Contact Details May Have Leaked Through a Vendor
Coinbase disclosed on October 28 that a security incident at analytics vendor Amplitude exposed contact information for a small subset of its customers, while the exchange stated its own systems were not accessed.
Coinbase has not suffered a data breach, but contact details for some users were exposed through an incident at analytics vendor Amplitude.
The exchange said it found no evidence of unauthorized access to its own systems and that customer funds remain safe.
Coinbase has not had a data breach. Amplitude, an analytics vendor, experienced a security incident which impacted a small subset of Coinbase customer contact data, among other Amplitude customers. We’ve found no evidence of unauthorized access to Coinbase systems.
Coinbase gives no figure
The company did not specify which contact fields were exposed or how many users were affected. An anonymous X account claimed attackers obtained details for more than 70,000 users, a figure not confirmed by Coinbase.
23pds, chief information security officer at security firm SlowMist, reshared the claim on X.
Coinbase has faced similar risks in the past. In May 2025, the exchange said criminals bribed overseas support contractors to gather customer records for impersonation scams.
Bithumb reports internal system breach
Coinbase is not the only exchange handling a leak this week. South Korean exchange Bithumb confirmed that an unauthorized outside party accessed its mobile groupware system used by staff.
The exchange reported the incident to the Korea Internet & Security Agency (KISA) and said the system sits apart from its trading platform, so customer crypto assets cannot be reached through the breach.
So far it appears to be focused on internal employee information, but we are analyzing the details while leaving open the possibility that member information was included.
Bithumb has a history of linking leaked contact data to financial losses. In 2017, a database stolen from an employee’s computer exposed phone numbers and emails for about 3% of customers, and the exchange later tied wallet thefts to phishing attacks.
Earnings update looms
The disclosure comes a day before Coinbase reports third-quarter earnings after the market closes on Thursday. Analysts expect revenue near $1.2 billion.
The incident occurred after the quarter closed on September 30, so any costs would more likely appear in fourth-quarter results. Still, a cost estimate in Thursday’s update would show whether the incident reaches Coinbase’s books.
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