Samsung has officially released the August 2025 security update for the Galaxy S21, Galaxy S21+, and Galaxy S21 Ultra trio, starting first in Korea. The new patch brings important Android security updates, helping devices launched since 2021 continue to maintain a high level of security even though they are no longer eligible for new features.

According to the record, the update is being deployed with a software codename ending in HYH5. Like previous times, the release process will take place in stages and take a few days to reach all domestic users, then expand to global markets, including the US.

Samsung has committed to 4 generations of operating system upgrades for the Galaxy S21. The device shipped with Android 11 and has been continuously upgraded to Android 15 with One UI 7. Therefore, this flagship series will not be upgraded to One UI 8 (Android 16), but will continue to receive regular security patches until at least early 2026.

Notably, the Galaxy S21 FE is still on the list of eligible One UI 8 upgrades because it was launched later, running Android 12 out of the box. The Android 16/One UI 8 update for the S21 FE is expected to be released later this year, and this will also be the last major OS upgrade for this series.

If you are using a Galaxy S21, the August 2025 patch will be available in the settings soon. This update fixes 47 security vulnerabilities, including a serious Android bug, and many issues affecting Galaxy devices. To check and download, users can go to Settings > Software update > Download and install.