diff --git a/onnxruntime/core/graph/ep_api_types.cc b/onnxruntime/core/graph/ep_api_types.cc
index 1864bfde31d22..1eb7d4f17e581 100644
--- a/onnxruntime/core/graph/ep_api_types.cc
+++ b/onnxruntime/core/graph/ep_api_types.cc
@@ -543,6 +543,10 @@ void EpGraph::IndexToEpNodeMap::Resize(NodeIndex min_node_index, NodeIndex max_n
 }
 
 EpNode* EpGraph::IndexToEpNodeMap::GetEpNode(NodeIndex node_index) const {
+  if (node_index < min_node_index_ || node_index >= min_node_index_ + nodes_.size()) {
+    return nullptr;
+  }
+
   size_t i = node_index - min_node_index_;
   assert(i < nodes_.size());
   return nodes_[i];