Samsung has started rolling out stable One UI 9, based on Android 17, to the Galaxy S26, S26+ and S26 Ultra. It's starting in South Korea, and people in the beta are getting the finished build first, with firmware ending in BZI6. The download is about 650MB and goes out in stages, so it can take a bit to show up even once it reaches your region.
The S26 flagships were oddly late here. The beta opened in May, and stable One UI 9 had already shipped in July on the Galaxy Z Fold 8 and Flip 8. Even the cheaper Galaxy S26 FE launched with the finished software first. What arrives includes My FanCam, which lets Galaxy AI pick a person out of a wider video and reframe the shot around them, plus customizable Now Brief cards and smarter Now Nudge suggestions.