As per the latest information, the update has been released for a bunch of Asian and South American countries which include Argentina, Brazil, Colombia, Cambodia, Chile, Kazakhstan, Malaysia, the Philippines, Russia, South Korea, Taiwan, Thailand, the UAE, Ukraine, Uzbekistan, and Vietnam.  It is always recommended to keep your device updated with the latest security patch available because it fixes different kinds of exploits that may harm your device. The April 2021 security patch for Samsung phones fixes 21 CVE’s (Common Vulnerabilities and Exposures) from Samsung and 30 CVE’s from Google. To update your Galaxy A8 (2018) with the latest build, navigate to Settings » Software updates and then tap on Download and install. The update carries different firmware versions depending on the regions. More details on the firmware versions are given below.

A530FXXSICUC4: Chile, Colombia (Movistar) A530FXXSICUD3: UAE A530FXXSICUD3: Cambodia, Kazakhstan, Malaysia, the Philippines, Russia, Taiwan, Thailand, Ukraine, Uzbekistan, and Vietnam A530FXXSICUD8: Argentia, Brazil, Colombia A530NKSU8CUC2: South Korea

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April 2021 security update reaches Samsung Galaxy A8  2018  - 55