JPMorgan Chase & Co. said Friday that one of its vendors reported that some Chase customers' email addresses were included in files that someone accessed without permission.
Someone outside Epsilon, a marketing firm JPMorgan Chase uses to send emails, gained access without permission to files that included some Chase customer emails, JPMorgan Chase said.
The bank said the affected files did not include customers' financial details.
It is advising customers of "everything we know as we know it," it said. And it reminded customers that it never requests personal information or credentials in an email.
Information and contact numbers are available at www.chase.com at the link marked "Please read important message to all Chase customers."
The bank, which offers financial products and services to consumers, governments and businesses through its J.P. Morgan and Chase brands, said it is working to confirm what happened.
Its shares added 9 cents to $46.44 after hours Friday. In regular trading, they rose 25 cents to close at $46.35.