Run the application below with a profiler attached. Make sure the window is narrow enough for the tabs menu to appear. Open and close the tabs menu, then close all tabs except one, then make a heap dump.

A typical heap dump is attached as tabs-menu-leak.zip. It shows 7 objects of type javafx.scene.control.Tab (there should be only one). Most of the objects are referenced from TabControlButtons.popup.skin.

import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.control.ContextMenu;
import javafx.scene.control.Label;
import javafx.scene.control.MenuItem;
import javafx.scene.control.Tab;
import javafx.scene.control.TabPane;
import javafx.scene.control.TextField;
import javafx.scene.input.KeyCombination;
import javafx.stage.Stage;

public class Test extends Application {

    @Override public void start(Stage stage) {
        TabPane tabs = new TabPane();
        for (int i=0; i<7; i++) {
            Label label = new Label("Label" + i);
            Tab tab = new Tab("Tab" + i);
            tab.setContent(label);
            tab.setContextMenu(createContextMenu());
            tabs.getTabs().add(tab);
        }
        stage.setScene(new Scene(tabs));
        stage.sizeToScene();
        stage.show();
    }
    
    ContextMenu createContextMenu() {
        MenuItem item = new MenuItem("Cut");
        item.setAccelerator(KeyCombination.keyCombination("Ctrl+X"));
        item.setOnAction(new EventHandler<ActionEvent>() {
            public void handle(ActionEvent ev) {}
        });
        return new ContextMenu(item);
    }

    public static void main(String[] args) {
        launch(args);
    }
}