Tinkerers, rejoice: Snapdragon-powered Galaxy S8+ has been successfully rooted
All facts point out that the Snapdragon 835+ (SM-G955) powered US version of the Samsung Galaxy S8+ has just been rooted.
SuperSU running on the Galaxy S8+
However, the root was achieved thanks to an exploit that did not allow the team to unlock the bootloader of the Galaxy S8+. Essentially, this means that adventurous tinkerers won't be able to flash TWRP or another custom recovery on the phone just yet.
As far as the Exynos-powered versions of the Galaxy S8 (SM-G950F) and S8+ (SM-G955F) go, their users are a tad luckier - both phones have been successfully rooted and have unlockable bootloaders, which opens the possibility for custom ROMs.