# UNDF: UNDF-2026-000000468
--- a/src/nodes/core/Node.js
+++ b/src/nodes/core/Node.js
@@ -346,18 +346,22 @@ class Node extends EventDispatcher {
 	 * Can be used to traverse through the node's hierarchy.
 	 *
 	 * @param {traverseCallback} callback - A callback that is executed per node.
+	 * @param {Set<Node>} [visited] - Internal visited set; prevents exponential
+	 *   re-visits on diamond-shaped DAGs (nodes shared by multiple parents).
 	 */
-	traverse( callback ) {
+	traverse( callback, visited = new Set() ) {

-		callback( this );
+		// CWE-407 fix: skip nodes already visited; was O(2^D) on diamond DAGs.
+		if ( visited.has( this ) ) return;
+		visited.add( this );

-		for ( const childNode of this.getChildren() ) {
+		callback( this );

-			childNode.traverse( callback );
+		for ( const childNode of this.getChildren() ) {

-		}
+			childNode.traverse( callback, visited );
+
+		}

 	}