We understand that many of our Magento 1 merchants need additional time to make the transition to newer versions of Magento.Magento software support and/or security maintenance applies only to Magento software and does not apply to third-party extensions or customizations. Maintenance of extensions, customization or other modifications to the Magento codebase, including compliance with security and privacy standards (PCI, SOC, ISO, etc.), are the express responsibility of the merchant.
Many merchants who are currently on Magento 1 will look to re-platform to Magento 2, and with Adobe releasing Commerce Cloud, it’s a great choice. However, this is also a great time to talk more generally about choosing the right eCommerce platform for your organization. Retailers currently on Magento 1 are in a perfect position to reevaluate their eCommerce platform decision, considering multiple facets of the customer experience like on-site personalization and targeted marketing options.
We encourage all Magento Commerce 1 customers to reach out to their Customer Success Managers or development partners to start their upgrade planning as soon as possible. Source From: https://adobe.ly/2lUqNSY
Magento Upgrade Service 