AT&T/ZDNETMillions of AT&T customers may have been affected by a data leak, forcing the carrier to change their passcodes. In a notice posted on Saturday, AT&T said that data seemingly from 2019 and earlier was leaked on the dark web, impacting 7.6 million current AT&T subscribers and 65.4 million former AT&T account holders.The scope of the leaked data found on the dark web varies from account to account. In addition to passcodes for all affected customers, it may also include full names, email addresses, mailing addresses, phone numbers, social security numbers, dates of birth, and AT&T account numbers. The carrier said that the dataset does not contain any personal financial information or call history.Also: Why were millions of AT&T customers left disconnected? We have an answerAT&T said the company sent emails or letters to all current and former subscribers who were impacted by the leak. In addition to resetting customer passcodes, the company urged customers to monitor their account activity and credit reports. To do so yourself, you can set up free fraud alerts with Equifax, Experian, and TransUnion, and review a free credit report through Freecreditreport.com.”The severity of this data breach is significantly heightened because of the Personal Identifiable Information (PII), including full names, email addresses, mailing addresses, phone numbers, Social Security numbers, dates of birth, AT&T account numbers, and passcodes, that were part of the compromised data,” Anne Cutler, a cybersecurity evangelist at Keeper Security, told ZDNET. “The immediate concern is the potential exploitation of this exposed data, which could lead to various malicious activities such as identity theft, phishing attacks, and unauthorized access to user accounts.”If you’re an AT&T subscriber affected by this breach, change your passcode. To do that, go to your myAT&T profile page and sign in when prompted. Scroll to the section for “My linked accounts,” select Edit for the passcode you want to change, and follow the prompts. More