While Samsung continues its development of One UI 8.5 behind the scenes, the tech giant hasn't forgotten its 2023 flagships. The company has officially begun deploying the December 2025 security update for the Galaxy S23 lineup, following earlier releases for the Galaxy S25 and S24 series.

According to initial reports, the rollout has kicked off in South Korea. Users of the Galaxy S23, S23+, and S23 Ultra in the region are currently receiving the new One UI 8-based firmware, identified by version number EYL1. Samsung is expected to expand availability to other global markets, including the United States, in the coming days.

This December Security Maintenance Release (SMR) is substantial, addressing nearly 70 security vulnerabilities across the Galaxy ecosystem. The patch combines critical Android OS fixes provided by Google with specific One UI refinements from Samsung. Given the severity of some patched vulnerabilities, users are strongly advised to install the update as soon as it becomes available.

To manually check for the update, users can navigate to Settings > Software Update > Download and Install. The system will ping Samsung’s servers and prompt a download if the firmware is live. A quick restart will be required to finalize the installation.

Although this update focuses purely on security rather than new features, a more significant overhaul is on the horizon. The One UI 8.5 update—currently in beta for select Galaxy S25 users—is slated for a stable release in 2026. It will likely debut on the Galaxy S26 series before trickling down to older devices, including the Galaxy S23.