AT&T has confirmed a significant data breach involving over 7.6 million current customers and 65 million former customers, The Verge reports.

The leaked data includes sensitive information such as full names, email addresses, mailing addresses, phone numbers, social security numbers, dates of birth, AT&T account numbers, and passcodes.

In response to the breach, AT&T has taken immediate action to reset the security passcodes of affected active customers.

The company is also reaching out to impacted customers via email or letter to inform them about the data that was compromised and the measures being taken to address the situation.

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The acknowledgment of the data leak comes after TechCrunch alerted AT&T to the vulnerability of its encrypted passcodes.

The passcodes, typically used for account security during phone calls with company support or in-store verification, were found to be "easy to decipher" by security researchers.

Although the leaked data does not include personal financial information or call history, AT&T is urging customers to set up free fraud alerts with credit bureaus Equifax, Experian, and TransUnion as a precautionary measure.

AT&T has stated that the leaked data appears to be from 2019 or earlier and has emphasized that there is currently no evidence of authorized access to its systems.

The company is working closely with external cybersecurity experts to analyze the situation further.

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In 2021, a data breach in T-Mobile, a mobile telecommunications company, exposed the information of over 40 million customers.