MailChimp had been leaking respondents’ email addresses.
The issue could expose personal information.
If one visit a link from a MailChimp newsletter, his email address and reading habits can be compromised to a site owner.
Source: https://www.infosecurity-magazine.com/news/mailchimp-found-leaking-email/
"id": "MAI225320522",
"linkid": "mailchimp",
"type": "Breach",
"date": "01/2018",
"severity": "85",
"impact": "4",
"explanation": "Attack with significant impact with customers data leaks"