It seems the Tomcat process is consuming most of your memory, tomcat is normally used for the CUCM webpage and webservices, from here you could be running into somekind of bug depending on your CUCM version.
As a quick workarround i would suggest you ssh into cucm vm that has the problemand issue the:
utils service restart Cisco Tomcat
This will impact the access to the cucm webpage for a few minutes but the phones will be able to recieve and place calls normally.
After this the memory should go down, and you can investigate further using Cisco Bug toolkit: