diff --git a/user/src/com/google/web/bindery/requestfactory/server/Resolver.java b/user/src/com/google/web/bindery/requestfactory/server/Resolver.java
index 363e0e847b..6da91316a1 100644
--- a/user/src/com/google/web/bindery/requestfactory/server/Resolver.java
+++ b/user/src/com/google/web/bindery/requestfactory/server/Resolver.java
@@ -411,9 +411,15 @@ private static Set<String> expandPropertyRefs(Set<String> refs) {
     }
 
     Set<String> toReturn = new TreeSet<String>();
+    final int maxDepth = 32; // bound per-ref prefix expansion (CWE-400)
     for (String raw : refs) {
+      int depth = 0;
       for (int idx = raw.length(); idx >= 0; idx = raw.lastIndexOf('.', idx - 1)) {
         toReturn.add(raw.substring(0, idx));
+        if (++depth > maxDepth) {
+          throw new ReportableException("Property reference exceeds the maximum depth of "
+              + maxDepth + ": " + raw);
+        }
       }
     }
     return toReturn;
diff --git a/user/src/com/google/web/bindery/requestfactory/server/SimpleRequestProcessor.java b/user/src/com/google/web/bindery/requestfactory/server/SimpleRequestProcessor.java
index af4dc80e1b..3d11092fd1 100644
--- a/user/src/com/google/web/bindery/requestfactory/server/SimpleRequestProcessor.java
+++ b/user/src/com/google/web/bindery/requestfactory/server/SimpleRequestProcessor.java
@@ -430,6 +430,10 @@ private void processInvocationMessages(RequestState state, RequestMessage req,
       // No method invocations which can happen via RequestContext.fire()
       return;
     }
+    if (invocations.size() > MAX_INVOCATIONS) {
+      throw new ReportableException("Request contained " + invocations.size()
+          + " invocations, exceeding the maximum of " + MAX_INVOCATIONS);
+    }
     List<Method> contextMethods = new ArrayList<Method>(invocations.size());
     List<Object> invocationResults = new ArrayList<Object>(invocations.size());
     Map<Object, SortedSet<String>> allPropertyRefs = new HashMap<Object, SortedSet<String>>();
@@ -462,6 +466,11 @@ private void processInvocationMessages(RequestState state, RequestMessage req,
         // Invoke it
         domainReturnValue = service.invoke(domainMethod, args.toArray());
         if (invocation.getPropertyRefs() != null) {
+          if (invocation.getPropertyRefs().size() > MAX_PROPERTY_REFS_PER_INVOCATION) {
+            throw new ReportableException("Invocation contained "
+                + invocation.getPropertyRefs().size()
+                + " propertyRefs, exceeding the maximum of " + MAX_PROPERTY_REFS_PER_INVOCATION);
+          }
           SortedSet<String> paths = allPropertyRefs.get(domainReturnValue);
           if (paths == null) {
             paths = new TreeSet<String>();
@@ -500,11 +509,25 @@ private void processInvocationMessages(RequestState state, RequestMessage req,
     }
   }
 
+  /**
+   * Maximum number of operations accepted in a single RequestFactory request, bounding the
+   * per-operation reflective work (CWE-400 / CWE-409).
+   */
+  private static final int MAX_OPERATIONS = 1000;
+  /** Maximum number of invocations accepted in a single RequestFactory request (CWE-400). */
+  private static final int MAX_INVOCATIONS = 1000;
+  /** Maximum propertyRefs accepted on a single invocation (CWE-400). */
+  private static final int MAX_PROPERTY_REFS_PER_INVOCATION = 100;
+
   private void processOperationMessages(final RequestState state, RequestMessage req) {
     List<OperationMessage> operations = req.getOperations();
     if (operations == null) {
       return;
     }
+    if (operations.size() > MAX_OPERATIONS) {
+      throw new ReportableException("Request contained " + operations.size()
+          + " operations, exceeding the maximum of " + MAX_OPERATIONS);
+    }
 
     List<AutoBean<? extends BaseProxy>> beans = state.getBeansForPayload(operations);
     assert operations.size() == beans.size();