Breach date: 2012-07-11. Added to this index: 2013-12-04. Accounts affected: about 453K. Domain: yahoo.com.
In July 2012, Yahoo! had their online publishing service "Voices" compromised via a SQL injection attack. The breach resulted in the disclosure of nearly half a million usernames and passwords stored in plain text. The breach showed that of the compromised accounts, a staggering 59% of people who also had accounts in the Sony breach reused their passwords across both services.
Breach data sourced from Have I Been Pwned, used under CC BY 4.0. Additional breach metadata provided by XposedOrNot. DataExposed is an independent service and is not affiliated with or endorsed by either.
The Yahoo breach exposed Email addresses, Passwords. About 453K accounts were affected.
Run the free email breach check with the address you used on that service. It will tell you whether your address appears in this dataset.
Change the password on that account and everywhere you reused it, then turn on two-factor authentication. Passwords from this breach are traded and tried automatically against other sites.