King Soopers, the state’s largest grocery chain, and Chase Ban are warning customers of a breach of a third-party vendor’s database that stores customer email addresses.

The breach occurred with a company called Epsilon, a vendor that manages email for the companies, both of which have major operations in Colorado.

Epsilon said an unauthorized person outside the company accessed the information; it did not disclose how the breach happened.

Both King Soopers and Chase said the breach did not involve customer financial or transaction data or credit cards.

King Soopers is Colorado’s largest supermarket chain.