Glossary
Data breach
Data breach: A data breach is a security incident in which a company's stored customer data, such as emails, passwords, Social Security numbers or card numbers, is stolen.
Updated February 1, 2027
An example
A health insurer announces that records including names, dates of birth and Social Security numbers were taken.
Why it matters to you
Your data has almost certainly been in a breach. The response is a credit freeze, unique passwords and two-factor authentication, not panic.
Where to go next
See also
- Credential stuffing
Credential stuffing is when attackers take email-and-password pairs leaked in one breach and try them automatically on thousands of other sites.
- Credit freeze
A credit freeze is a free setting at each of the three credit bureaus that blocks anyone from opening a new account in your name until you lift it.
- Identity theft
Identity theft is the use of your personal information, such as your Social Security number or date of birth, to open accounts, file tax returns or get medical care in your name.