Personal information of T-Mobile’s wireless customers, including names, addresses, phone numbers and more, was exposed in a recent breach.

T-Mobile told TechCrunch that the breach impacted less than 1.5 percent of its 84.2 million customers, or approximately 1.26 million people. The breach occurred earlier this month, and customer financial information, including credit card numbers, was not compromised, the company said.

“Our Cybersecurity team discovered and shut down malicious, unauthorized access to some information related to your T-Mobile prepaid wireless account,” the company wrote in a message to customers affected by the breach. “We promptly reported this to authorities. None of your financial data (including credit card information) or social security numbers was involved, and no passwords were compromised.”

A T-Mobile spokeswoman added that “like any other company, T-Mobile is unfortunately not immune to this type of criminal attack. We have a number of safeguards in place to protect personal information from unauthorized access, use, or disclosure. Fortunately, we discovered this activity quickly and shut it down immediately.”

Data breaches have been on the rise in recent years, and the number of attacks rose 54 percent in the first six months of 2019 compared to the previous year, according to a report from Risk Based Security. T-Mobile suffered a previous breach in August 2018 that affected roughly 3 percent of its customers.

The breach comes at an important time for the company. It is pushing to close the mega-merger with Sprint, and recently showed off a series of benefits the combined company could provide for customers. Last week, T-Mobile CEO John Legere announced plans to step down from the top job next year.