--- a/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/linker/BrowserJSObjectLinker.java	Mon Sep 28 08:40:39 2015 +0200
+++ b/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/linker/BrowserJSObjectLinker.java	Mon Sep 28 18:58:52 2015 +0530
@@ -107,9 +107,10 @@
             return null;
         }
 
-        final GuardedInvocation inv;
+        GuardedInvocation inv;
         if (jsObjectClass.isInstance(self)) {
             inv = lookup(desc, request, linkerServices);
+            inv = inv.replaceMethods(linkerServices.filterInternalObjects(inv.getInvocation()), inv.getGuard());
         } else {
             throw new AssertionError(); // Should never reach here.
         }

--- a/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/linker/JSObjectLinker.java	Mon Sep 28 08:40:39 2015 +0200
+++ b/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/linker/JSObjectLinker.java	Mon Sep 28 18:58:52 2015 +0530
@@ -77,9 +77,10 @@
             return null;
         }
 
-        final GuardedInvocation inv;
+        GuardedInvocation inv;
         if (self instanceof JSObject) {
             inv = lookup(desc, request, linkerServices);
+            inv = inv.replaceMethods(linkerServices.filterInternalObjects(inv.getInvocation()), inv.getGuard());
         } else if (self instanceof Map || self instanceof Bindings) {
             // guard to make sure the Map or Bindings does not turn into JSObject later!
             final GuardedInvocation beanInv = nashornBeansLinker.getGuardedInvocation(request, linkerServices);

--- a/test/src/jdk/nashorn/api/scripting/test/PluggableJSObjectTest.java	Mon Sep 28 08:40:39 2015 +0200
+++ b/test/src/jdk/nashorn/api/scripting/test/PluggableJSObjectTest.java	Mon Sep 28 18:58:52 2015 +0530
@@ -27,6 +27,7 @@
 
 import static org.testng.Assert.assertEquals;
 import static org.testng.Assert.assertFalse;
+import static org.testng.Assert.assertTrue;
 import static org.testng.Assert.fail;
 
 import java.nio.IntBuffer;
@@ -34,9 +35,11 @@
 import java.util.HashMap;
 import java.util.LinkedHashMap;
 import java.util.Set;
+import javax.script.Invocable;
 import javax.script.ScriptEngine;
 import javax.script.ScriptEngineManager;
 import jdk.nashorn.api.scripting.AbstractJSObject;
+import jdk.nashorn.api.scripting.ScriptObjectMirror;
 import org.testng.annotations.Test;
 
 /**
@@ -286,4 +289,23 @@
             fail(exp.getMessage());
         }
     }
+
+    // @bug 8137258: JSObjectLinker and BrowserJSObjectLinker should not expose internal JS objects
+    @Test
+    public void hidingInternalObjectsForJSObjectTest() throws Exception {
+        final ScriptEngineManager engineManager = new ScriptEngineManager();
+        final ScriptEngine e = engineManager.getEngineByName("nashorn");
+
+        final String code = "function func(obj) { obj.foo = [5, 5]; obj.bar = {} }";
+        e.eval(code);
+
+        // call the exposed function but pass user defined JSObject impl as argument
+        ((Invocable)e).invokeFunction("func", new AbstractJSObject() {
+            @Override
+            public void setMember(final String name, final Object value) {
+                // make sure that wrapped objects are passed (and not internal impl. objects)
+                assertTrue(value.getClass() == ScriptObjectMirror.class);
+            }
+        });
+    }
 }