No. From the CU6 version onwards, Trados GroupShare is not using the Apache Log4j utility/library anymore.
The optional web client application MultiTerm Online is not using the affected versions of Log4j. it use Log4j 1.2.13. And the vulnerability impacts all Log4j versions higher than or equal to 2.0-beta9 and lower than 2.15. Further, MultiTerm Online does not have JMSAppender configured.
The logging configuration can be checked under the Apache Tomcat folder\webapps\multiterm\WEB-INF\classes\log4j.properties
A new update for MultiTerm Online using a newer 2.x version of Log4j will be released soon.