Magento 2.0.18 is the final 2.0.x release. After March 2018, Magento 2.0.x will no longer receive security patches, quality fixes, or documentation updates.
To maintain your site's performance, security, and PCI compliance, upgrade to the latest version of Magento.

Update the Magento application

This topic discusses how a contributing developer can update the Magento application without reinstalling it. To perform an upgrade if you’re not a contributing developer, see Updating the Magento application and components.

To update the Magento software if you’re a contributing developer:

  1. Log in to your Magento server as, or switch to, the Magento file system owner.
  2. Save any changes you made to composer.json because the following steps will overwrite it:

     cd <your Magento install dir>
     cp composer.json composer.json.old
    
  3. Update your local repository to get the latest code:

    git pull origin develop
    

    If git pull origin develop fails, see troubleshooting.

  4. Diff and merge your composer.json.old with composer.json installed with the Magento software.
  5. Enter the following command:

    composer update
    
  6. Update the Magento database:

    php <your Magento install dir>/bin/magento setup:upgrade