Arc System Works suspends all websites for PHP security work

Arc System Works announced on October 23, 2026 that it is temporarily suspending every website and web service it operates, in order to carry out additional maintenance tied to a PHP security response. The company has not given an end time for the suspension, according to gamebusiness.jp.

At the time of writing, the company's official website was inaccessible. Online play of the company's games, including matchmaking and lobbies, is not affected by the suspension.

The new round of work follows PHP-related maintenance that began on October 22. On that day at 18:00, Arc System Works announced emergency PHP security maintenance on its official X account, suspending several official sites and Players Guilds, including those for Guilty Gear -Strive-, BlazBlue Centralfiction and Persona 4 Arena Ultimax.

Wider PHP problems across the industry

In October 2025, The PHP Group disclosed two vulnerabilities rated 9.2 on CVSS v4.0, with fixes released the following day. From the night of October 21, 2025, numerous games and related services ran emergency maintenance, and most major titles had recovered by October 22, 2025.

Some long-running titles did not return. World Quest and Boku no Makai wo Sukutte! decided to end service because addressing the vulnerability was judged too difficult, while Rage of Bahamut, running since 2011, requires a major update from an old version and its maintenance is expected to exceed one week. Ace Combat 8 postponed an update due to a system-related incident affecting the industry, without directly mentioning PHP.