Nintendo yanks Wii U Mario Kart 8 and Splatoon offline due to security concerns
Expects "extended maintenance duration".
If you had high hopes of hunkering down for a spot of Wii U Mario Kart 8 or Splatoon multiplayer this weekend, there's some bad news: Nintendo has pulled both games offline while it addresses a security vulnerability, with no hint as to when servers may return.
Nintendo took both games offline at 4.30am this morning in the UK, and confirmed the downtime on its server status page, explaining, "This network service is currently unavailable due to urgent maintenance required to fix a vulnerability related to online play."
As noted by VGC, Nintendo dataminer OatmealDome has suggested the security issue affecting Mario Kart 8 and Splatoon is likely to be ENLBufferPwn - a vulnerability common to network code present in a number of first-party Nintendo games that makes it possible for a hacker to connect to another player's device and remotely execute code.
To date, ENLBufferPwn has been identified across a number of 3DS, Wii U, and Switch games, but while most of these have now been fixed by Nintendo - including Mario Kart 8 Deluxe, Animal Crossing: New Horizons, Nintendo Switch Sports, and Splatoon 3 - Mario Kart 8 and Splatoon on Wii U were still outstanding until today.
It remains uncertain how long online multiplayer will remain unavailable across both games, but Nintendo says it expects "an extended maintenance duration" while it addresses the issue.