London North Eastern Railway (LNER) has warned passengers to remain vigilant after a cyber-attack on a third-party supplier exposed customer contact details and some journey history. The operator stressed that no financial data, passwords or ticketing systems had been compromised and that train services continue to run as normal. The breach, which LNER said it was treating “with the highest priority”, highlights the growing risk of cyber-attacks on UK transport operators and their supply chains. The incident is the latest in a string of high-profile hacks to hit UK businesses and transport services. Transport for London suffered a cyber breach last year affecting financial data for 5,000 customers, while earlier this month production at Jaguar Land Rover was halted by a ransomware attack.