Data breaches → CoinMarketCap
Was your data in the CoinMarketCap breach?
2021 · coinmarketcap.com · ~3,117,548 accounts exposedLow severity · 2/10
CoinMarketCap (coinmarketcap.com) suffered a data breach in 2021 that exposed around 3,117,548 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
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."
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 CoinMarketCap breach exposed and what each item actually enables:
Puts you on spam and phishing lists, and confirms to attackers that you hold an account with this service — which makes impersonation emails more believable.
What to do if you were affected
These steps are ordered for this specific breach — the most urgent action given what leaked comes first.
- Email addresses: Treat any message referencing this service with suspicion, and never act on links in unexpected emails.
- Check whether your own email appears in this breach — run a free scan to confirm before you spend time on the steps above.
How urgent is this now?
This data has been circulating for around 5 years, which means it has been copied, combined with other leaks and indexed by search tools many times over.
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
What data was exposed in the CoinMarketCap breach?
The CoinMarketCap breach exposed email addresses. Puts you on spam and phishing lists, and confirms to attackers that you hold an account with this service — which makes impersonation emails more believable.
How many people were affected by the CoinMarketCap breach?
Around 3,117,548 accounts were exposed, making it a large breach.
What should I do if I had a CoinMarketCap account?
Treat any message referencing this service with suspicion, and never act on links in unexpected emails. You can check whether your own email appears in this breach with a free Nullivo scan — no password required.
Breaches that exposed similar data
If the CoinMarketCap breach affected you, these breaches exposed comparable information — worth checking too, since leaked datasets are routinely combined.
- Was your data in the MangaDex breach? (2021, ~2,987,329 accounts)
- Was your data in the FlexBooker breach? (2021, ~3,756,794 accounts)
- Was your data in the IDC Games breach? (2021, ~3,966,871 accounts)
- Was your data in the Adecco breach? (2021, ~4,284,538 accounts)
- Was your data in the Emotet breach? (2021, ~4,324,770 accounts)
- Was your data in the Gemplex breach? (2021, ~4,563,166 accounts)