SAP WebCUIF cannot support browser versions that vendors no more support themselves. The corresponding SAP Note 1746385 - Main WEBCUIF Browser Support Note has been updated. Following is an abstract from this note, but you should always check and follow SAP Note 1746385 which will be updated timely.
WEBCUIF has to support different browser versions, as those come and go.
●SAP WebCUIF cannot support browser versions that vendors no more support themselves.
Beginning January 12, 2016, the following operating systems and browser version combinations will be supported:
Windows Platform Internet Explorer Version
Windows Vista SP2 Internet Explorer 9
Windows Server 2008 SP2 Internet Explorer 9
Windows 7 SP1 Internet Explorer 11
Windows Server 2008 R2 SP1 Internet Explorer 11
Windows 8.1 Internet Explorer 11
Windows Server 2012 Internet Explorer 10
Windows Server 2012 R2 Internet Explorer 11
After January 12, 2016, only the most recent version of Internet Explorer available for a supported operating system will receive technical support and security updates. For example, customers using Internet Explorer 8, Internet Explorer 9, or Internet Explorer 10 on Windows 7 SP1 should migrate to Internet Explorer 11 to continue receiving security updates and technical support."
●As soon as a vendor releases a new browser version, SAP WebCUIF commits to fix any issue as soon as possible, via Notes when possible, and SPs for complete solutions.
Additionally, Please also check following blog about how to find if Safari and Google Chrome are supported or not by CRM Interaction Center.