Update #2: The Apple Developer Center is back up after downtime.

Update: Downtime may be due to a recently discovered vulnerability. See after the jump for details.

Apple’s developer center has been unavailable over the past few hours without explanation. It’s not uncommon to see the site go down for a few hours near announcement events, but today’s reason might be more ominous. Multiple developers across Twitter are postulating that the downtime may be due to a hack.

A few developers have noticed that their developer profile addresses are now showing an address in Russia instead of their own. This has led some to speculate that maintenance in regards to a hack is behind the developer center’s downtime.

While developers may not need to access the site every moment of the day, it can cause development downtime. When compiling code using Apple’s development software Xcode, sometimes the application needs to phone home for code-signing requirements. This means that many devs can be left out in the cold while awaiting Apple’s maintenance.

All my teams on Developer Member Center at @apple are registered in Russia. Nice. pic.twitter.com/kyYyRyLTR7

— Dal Rupnik (@TheLegoless) September 6, 2017

It looks like @Apple Developer accounts got hack! All the profiles lists this Russian address under membership, Check your profiles pic.twitter.com/4OxhpakgPy

— Kais K. (@Kaiusee) September 6, 2017

Apple Dev Center down for maintenance because of a hack? https://t.co/b5vyIfm85p

— Steve T-S (@stroughtonsmith) September 6, 2017

Apple currently lists seven different types of maintenance on the developer System Status page.

When you can’t build your #ios app because Apple Developer servers are undergoing maintenance -_- pic.twitter.com/LNSVllKjq1

— Josh Lieberman (@JALsnipe) September 6, 2017

Update: A few years ago, Apple’s Developer Center suffered a four-day outage required by a complete overhaul of their internal systems. At that time, the outage was speculated to be caused by a vulnerability in Apache Struts 2.

A patch for the vulnerability was released today, and Apple may be slowly working through getting it applied onto their servers. It may also be possible that the servers were exploited using this vulnerability and Apple is in the mitigation stages now.

Hey @gregbarbosa it’s probably down to patch against this exploit, or because they didn’t patch in time: https://t.co/qtrGtmoFzV https://t.co/gStlBJNFtG

— Geekable (@geekable) September 6, 2017