Hackers have probably captured the data of almost 300,000 customers of the Japanese car company Toyota.
The group announced this on Friday in the city of Toyota.
"We have determined that 296,019 customer email addresses and associated administrative numbers may have been compromised," a press release said.
Accordingly, drivers who use the Toyota online service T-Connect are affected.
It was not announced whether Toyota customers from Germany were also affected.
Toyota Germany could not be reached for a statement to the dpa news agency on Friday.
The company in Japan said there was no possibility that other data such as names, phone numbers, credit cards or other information was leaked.
Nevertheless, experts rate such incidents as serious, because the basic information captured can be used to launch more dangerous phishing attacks on those affected.
The latest incident is in a series of data leaks and cybersecurity incidents at the Japanese company and its suppliers.
In March 2019, the data of 3.1 million customers fell into the hands of hackers.
This February, Toyota had to temporarily shut down production facilities after a supplier was hit by a cyber attack.
In the current case, the weak point was apparently also with a supplier.
He put part of the T-Connect program code on the Github platform and accidentally made the code available to the public in December 2017.
"The published source code contained an access key to the data server, which gave access to email addresses and customer management numbers."