Telstra, Australia’s largest telecoms operator, said on Sunday that 132,000 customers were impacted by an internal error that led to disclosure of customer details.
Telstra, which has 18.8 million customer accounts in Australia, said an internal review found the details were made publicly available due to a misalignment of databases.

Telstra’s blog post said some customers’ names, numbers and addresses were listed when they should not have been.

“We are removing the identified impacted customer details from the Directory Assistance service and the online version of the White Pages,” Telstra chief financial officer Michael Ackland said in a statement.

The disclosure comes after the company in October suffered a small data breach, attributing it to third-party intrusion that exposed some employee data back to 2017.

A Telstra internal staff email put the number of affected current and former employees of that breach at 30,000, according to local media.

Regarding the current issue, Ackland said “no cyber activity was involved”.

“Protecting our customers’ privacy is absolutely paramount and this is an unacceptable breach of their trust,” he added.

“We are in the process of contacting every impacted customer to let them know what has occurred.”

Optus, owned by Singapore Telecommunications, revealed on Sept. 22 that a system breach may have compromised up to 10 million accounts.