As described in Bug 1067260, the following commit fixes the issue.
There is no corresponding JIRA, though the same fix has already been committed in the upstream as well (WildFly 8.0.0.Final/JBoss Remoting 4.0.0.Final).
An EJB client on Tomcat was leaking threads like "ejb-client-context-tasks-463-thread-2" during a load test. From a heap dump, a Set object, org.jboss.remoting3.remote.RemoteConnectionProvider.pendingInboundConnections, was holding so many IoFuture objects. I found a related fix on the Set object between JBoss Remoting 3.2.18 (bundled with EAP 6.2.0 and CP01) and 3.2.19. That is only the major fix between those versions. The customer tested with JBoss Remoting 3.2.19 and corresponding jboss-client.jar, and confirmed the leak resolved.
MEAD build: https://brewweb.devel.redhat.com/buildinfo?buildID=338023
RPM6 wrapper: https://brewweb.devel.redhat.com/buildinfo?buildID=338027
RPM5 wrapper: https://brewweb.devel.redhat.com/buildinfo?buildID=338030
PR for EAP: https://github.com/jbossas/jboss-eap/pull/964
Verified on 6.2.2.CP.CR2.