Samsung has restricted security updates for Galaxy S21 series flagships

Samsung has officially announced that the Galaxy S21 series will no longer receive monthly security updates. Instead, the Galaxy S21, Galaxy S21+ and Galaxy S21 Ultra models will only be updated 4 times a year, which is quarterly.
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This decision is due to the fact that the devices are already outdated and the company decided to reduce the frequency of updates. However, Galaxy S21 FE owners can rest easy as their devices will continue to receive monthly updates until early next year.
When launching the Galaxy S21 series in 2021, Samsung promised 4 years of major OS updates and 5 years of security updates. The devices are expected to receive an update to Android 15 in the coming weeks, which will be the last major update for these models. Meanwhile, the Galaxy S21 FE will receive another major update to Android 16 when it is released by Google later this year.
Galaxy S21 users are advised to consider upgrading to newer models like the Galaxy S24 or Galaxy S25, which already offer 7 years of Android updates and 7 years of security updates.
Source: Samsung