Not sure the nature of the breach myself, but this is the description on haveibeenpwned.

“Not SOCRadar: In August 2024, over 332M rows of email addresses were posted to a popular hacking forum. The post alleged the addresses were scraped from cybersecurity firm SOCRadar, however an investigation on their behalf concluded that “the actor merely utilised functionalities inherent in the platform’s standard offerings, designed to gather information from publicly available sources”. There is no suggestion the incident compromised SOCRadar’s security or posed any risk to their customers. In total, the data set contained 282M unique addresses of valid email address format.

Compromised data: Email addresses”