Videogame developer Epic Games informed customers on Tuesday that several of its forums have been breached. The hackers reportedly gained access to information associated with more than 800,000 user accounts.

According to the company, the attackers obtained email addresses and other data from the Unreal Engine and Unreal Tournament forums, but passwords are not affected as they are stored in a different location.

On the other hand, Epic Games believes hackers managed to access email addresses, salted passwords and other data from legacy forums covering Infinity Blade, UDK, previous Unreal Tournament games, and Gears of War (archived forums). Users who have been active on these forums since 2015 have been advised to change their passwords.

The company initially said the Unreal Engine and Unreal Tournament forums will remain online and no passwords need to be reset. However, at the time of writing, all of the affected forums are offline for maintenance.

LeakedSource told ZDNet that more than 800,000 user accounts were obtained by an unnamed hacker who exploited a SQL injection vulnerability in the vBulletin software powering the forums. Epic Games had been using version 4.2.2 of vBulletin, which is known to be plagued by several flaws.

“This breach is another reminder that SQL injection -- which has been around since 1998 -- doesn’t appear to be going away anytime soon,” Deral Heiland, research lead at Rapid7, told SecurityWeek. “Current reporting of this event indicates that vBulletin forum software was still in use with a known SQLi vulnerability. While it is absolutely critical that we ensure all of our installed software is patched with the latest, secure version, it’s not entirely uncommon that IT administrators and security professionals don’t have a running tally of every software version deployed in their environment.”

LeakedSource said the leaked information also included IP addresses, dates of birth, private messages, and access tokens for social media accounts. The compromised password hashes are reportedly not easy to crack.

This was not the first time hackers breached Epic Games forums. In July 2015, the company reset user passwords after hackers gained access to usernames, email addresses, passwords and other data. The forums were running vBulletin 4.2.0 at the time.

Earlier this month, LeakedSource reported that hackers stole the email addresses, IPs, usernames and passwords of nearly 2 million users who had registered accounts on the official Dota 2 forum.

Related: User Data Leaked From Analytics Company Social Blade