A new test build for the international Galaxy S25 Ultra has been spotted, according to Tarun Vats. The firmware is S938BXXUDDZJB, and the post says it replaces an earlier build ending in UDDZJA. It arrives shortly after the S25 series received its October 2026 security update, but a test build alone doesn’t confirm a release date or what the update contains.
| Detail | Info |
| Phone | Galaxy S25 Ultra, international model (SM-S938B) |
| PDA and phone build | S938BXXUDDZJB |
| CSC build | S938BOXMDDZJB |
| Previous build (per the post) | S938BXXUDDZJA |
| Current public build | S938BXXUCDZIF (stable One UI 9) |
| Status | Test build, not on public firmware lists |
| Changelog and release date | Not available |
The post reportedly calls this the November update and says it will focus on One UI 9 optimizations and bug fixes. That is the post’s own description, and the firmware itself doesn’t show it. We couldn’t find S938BXXUDDZJB or UDDZJA on the public firmware list we checked, where the newest international S25 Ultra build is still S938BXXUCDZIF with a September 20 date, so neither the build nor its changelog can be checked. The letter J in the build number stands for October, so the build string points to October rather than November, and the November label should be treated as an interpretation.
In Samsung’s naming, builds starting with XXU are often used for larger updates, while XXS usually marks security-only updates, and the S25 Ultra’s current stable build is already a U build. The step from UC to UD suggests a newer revision, but it doesn’t say whether the build adds fixes, performance changes or anything new. It also isn’t clear whether it is an internal test, a candidate for a future stable update or an early version of the November security patch. No new features have been mentioned, so there is no basis yet for expecting new Galaxy AI tools, camera changes or battery improvements.
A similar test build was spotted a day earlier for the international Galaxy S24 Ultra. There’s nothing to install for now. S25 Ultra owners can check Settings, Software update, Download and install, but this build isn’t available to users.
M Adnan Akram is the founder and lead writer at Phoonomo, covering mobile technology with a primary focus on Samsung and the broader smartphone industry, alongside emerging developments in AI. He follows product launches, spec leaks, and industry trends closely to keep readers informed with timely updates.
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