iOS 4.2.7 is available for CDMA iPhone 4 users on Verizon, with iOS 4.3.2 for GSM iPhone 4, iPad 2, iPad, iPod touch 3G/4G. To update to iOS 4.2.7, connect iPhone 4 with your computer via USB and start iTunes. Click on “Download and Install” (Mac OS X) or “Download and Update” (Windows) button at prompt to get the new firmware 4.2.7. The last major update for Verizon iPhone was iOS 4.2.6, released in February 2011.
Apple has released iOS 4.2.6 for Verizon iPhone 4. The firmware file is 652mb in size, and has build number 8E200. The main difference between iOS 4.2.6 and iOS 4.2.1 for the current GSM iPhone 4 is the “Personal Hotspot” feature, which will be available for GSM iPhones starting with iOS 4.3.