No One UI 8, But Galaxy S21 Series Receives Latest Security Fixes

The Galaxy S21 series may have reached the end of its major upgrade journey, but it hasn’t been abandoned. While the 2021 flagships won’t get One UI 8, Samsung has now released the latest security patch for them. The update is available in the US, starting with carrier-locked units. It should soon expand globally.

Galaxy S21 series receives the September security update

Samsung is rolling out the September 2025 security update to the Galaxy S21, S21+, and S21 Ultra in the US. The update comes with the firmware build version HYI1 and appears to bring nothing more than the latest security fixes. Last month’s release addresses several dozen vulnerabilities across the Android system and Samsung’s One UI services, ensuring devices remain protected against new threats.

Launched in early 2021, the Galaxy S21 phones are now on their last legs. They have already stopped receiving feature updates, with One UI 7 being the final release. From here on, they will only receive security patches until sometime in 2026, after which Samsung will officially retire the series.

Though the latest package doesn’t add new features, it reinforces stability and security for day-to-day use. Users should still consider upgrading to a newer model — starting with the Galaxy S24 series, Samsung offers seven years of updates for its flagships, including seven major Android OS/ One UI versions. If you are interested, the Galaxy S25 Ultra is currently available at a handsome discount.

Note that the Galaxy S21 FE isn’t part of the original S21 lineup (FE models have always launched separately) and is still eligible for One UI 8. It debuted nearly a year after the flagship trio, shipping with a newer version of Android. One UI 8 will be its final major OS release, with the update expected later this month. Stay tuned for more.