3.12M accounts from CoinMarketCap (coinmarketcap.com) were exposed in this breach. Besides email addresses, it included some other data.
Was your email address in this breach?
We display where your address leaked and what went with it. We never store the address.
We don't store your address. It is checked right here against about 1029 breaches, including this one.
Email addresses
During October 2021, 3.1 million email addresses with accounts on the cryptocurrency market capitalisation website CoinMarketCap were discovered being traded on hacking forums. Whilst the email addresses were found to correlate with CoinMarketCap accounts, it's unclear precisely how they were obtained. CoinMarketCap has provided the following statement on the data: "CoinMarketCap has become aware that batches of data have shown up online purporting to be a list of user accounts. While the data lists we have seen are only email addresses (no passwords), we have found a correlation with our subscriber base. We have not found any evidence of a data leak from our own servers — we are actively investigating this issue and will update our subscribers as soon as we have any new information."
Source: Have I Been Pwned (CC BY 4.0)