Here is the stack got by user of wildfly CLI. Seems that some checks are missing when doing the substring.
/subsystem=mail:read-resource-description(operations=true, notifications=true, inherited=false)Exception in thread "Aesh Process Loop 2130192211" java.lang.StringIndexOutOfBoundsException: String index out of range: 95
at java.lang.String.substring(String.java:1963)
at org.jboss.aesh.console.AeshConsoleBuffer.performAction(AeshConsoleBuffer.java:535)
at org.jboss.aesh.console.AeshInputProcessor.parseOperation(AeshInputProcessor.java:139)
at org.jboss.aesh.console.Console.processInternalOperation(Console.java:775)
at org.jboss.aesh.console.Console.execute(Console.java:735)
at org.jboss.aesh.console.Console.access$900(Console.java:73)
at org.jboss.aesh.console.Console$6.run(Console.java:644)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)