Download Android Jelly Bean 4.2.2 stock firmware for CMX AML8726-MX TV Box from here or here.
Archive: CMX AML8726-MX Box-174073-20140927
Image file name: g18ref-ota-20140925.zip
Build number: g18ref-user 4.2.2 JDQ39 20140925 test-keys
Archive: CMX AML8726-MX Box-174073-20140927
Image file name: g18ref-ota-20140925.zip
Model: CMX AML8726-MX TV Box
Firmware: Android Jelly Bean 4.2.2 stock firmware
Image file size: 490 MB
Platform: Amlogic AML8726-MXFirmware: Android Jelly Bean 4.2.2 stock firmware
Image file size: 490 MB
Build number: g18ref-user 4.2.2 JDQ39 20140925 test-keys