Tesco experienced a data security incident on March 2020.
A database of stolen usernames and passwords from other platforms had been tried out on its websites.
No financial data was accessed and its systems have not been hacked.
Tesco issued new cards to 600,000 Clubcard account holders after unearthing a security issue.
Source: https://www.bbc.com/news/technology-51710687
"id": "TES14324423",
"linkid": "-tesco",
"type": "Data Leak",
"date": "03/2020",
"severity": "50",
"impact": "1",
"explanation": "Attack without any consequences"