Engine giant Unity has told developers to take "immediate action" after disclosing that there's been a security vulnerability in its tech for years. 

In a post on its website, the company's director of community and advocacy Larry "Major Nelson" Hryb wrote that there had been a security vulnerability in the engine since its 2017.1 version across Android, Windows, Linux and MacOS. 

He added that the company had fixed the problem and hadn't discovered anyone actually using this vulnerability to any end. Said vulnerability was discovered by security researcher RyotaK. 

Developers are urged update their game if they have released a title using Unity 2017.1 or later. 

"There is no evidence of any exploitation of the vulnerability, nor has there been any impact on users or customers," Hryb said.

"We have proactively provided fixes that address the vulnerability, and they are already available to all developers."