Danny Weber
An early Samsung build with model code S958U may point to initial software testing for the Galaxy S27 Ultra ahead of its expected 2027 launch.
Samsung has only just begun rolling out One UI 9, yet firmware for the next update has already appeared on the company’s internal test servers. The build is linked to the still-unannounced Galaxy S27 Ultra and an early version of One UI 9.5. According to insider Fahad Ali Javed, the firmware carries the number S958USQU0AZH3. The S958U identifier is believed to refer to the US version of the Galaxy S27 Ultra and fits Samsung’s usual model-numbering system. For comparison, the US Galaxy S26 Ultra is designated SM-S948U.
References to One UI 9.5 and the Galaxy S27 series had already been found in the interface code. The appearance of a complete test firmware may indicate that Samsung has moved from internal placeholders to early software validation. No screenshots or details about new One UI 9.5 features have surfaced yet. The timing matches Samsung’s previous development cycles: One UI 8.5 was also spotted on company servers several months before its debut with the Galaxy S26 lineup.
The stable One UI 9 release is currently available only on the Galaxy Z Fold 8, Galaxy Z Fold 8 Ultra and Galaxy Z Flip 8, while the Galaxy S26 series remains in beta testing. One UI 9.5 is expected to debut with the Galaxy S27 family in early 2027 and later reach older flagship devices.
It remains unclear which interface changes and new features will be included. More details may emerge as additional test builds appear.
© A. Krivonosov