Xiaomi continues to release updates to the Mi A3, nearly three years after announcing the smartphone. Presumably on its penultimate update, the Mi A3 started life on Android 9.0 Pie before finishing on Android 11. However, Xiaomi promised to deliver three years' worth of security patch updates, which it is almost on the verge of honouring. While this month's update falls on the device's third anniversary, Xiaomi did not release it until July 24, 2019. Hence, we suspect that Mi A3 will be greeted by at least one more security update before Xiaomi casts it adrift.
This month's update arrives as V12.0.25.0.RFQMIXM, denoting that it is for MIUI's global channel. For context, European versions of the Mi A3 last received an update in June, meaning a comparable update should be headed to the EEA channel soon. As the screenshot below shows, V12.0.25.0.RFQMIXM is over an 8 MB download that updates the Mi A3 to the July 2022 security patch. You can read what security improvements this month's security patch brings by reading the latest Android Security Bulletin.
However, you must check within Settings to determine which security patch level Xiaomi has installed. For some reason, Google continues to distribute security patch levels on the first of the month, followed by a second a few days afterwards. As it stands, V12.0.25.0.RFQMIXM should arrive as an over-the-air (OTA) update for eligible Mi A3 units. Alternatively, you can download the full ROM from Xiaomi's servers, available via Xiaomi Firmware Updater.