Samsung Begins Staged May Security Patch Rollout to Galaxy S25

The update patches critical Android vulnerabilities with One UI 8.5 sometimes required as a prerequisite.

Overview

Samsung started delivering the May 2026 security update to the Galaxy S25 series in a staged OTA that began rolling out on Wednesday to users in India.
The S25 build carries firmware S93xBXXS9CZE1 and is about 544–550MB in size, reflecting a sizeable package that focuses on security rather than new features.
Samsung says the patch fixes 36 security issues, including two critical flaws and roughly 30 CVEs that originate from Google’s Android security bulletin and Samsung’s own fixes.
Rollout remains staged and region-dependent so many owners will not see the update immediately; users can check manually in Settings > Software update > Download and install.
Samsung recently pushed stable One UI 8.5 to S25 models and is testing One UI 9.0 (Android 17) on the S26 series, which helps explain the staggered sequencing and may affect when different S25 models receive the patch.