diff -r 48c4eec2b7e6 -r 8c2e4d02f4ef wp/wp-includes/rest-api/endpoints/class-wp-rest-widgets-controller.php
--- a/wp/wp-includes/rest-api/endpoints/class-wp-rest-widgets-controller.php	Fri Sep 05 18:40:08 2025 +0200
+++ b/wp/wp-includes/rest-api/endpoints/class-wp-rest-widgets-controller.php	Fri Sep 05 18:52:52 2025 +0200
@@ -133,9 +133,14 @@
 	 * @since 5.8.0
 	 *
 	 * @param WP_REST_Request $request Full details about the request.
-	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
+	 * @return WP_REST_Response Response object.
 	 */
 	public function get_items( $request ) {
+		if ( $request->is_method( 'HEAD' ) ) {
+			// Return early as this handler doesn't add any response headers.
+			return new WP_REST_Response( array() );
+		}
+
 		$this->retrieve_widgets();
 
 		$prepared          = array();
@@ -677,7 +682,13 @@
 			);
 		}
 
-		$widget    = $wp_registered_widgets[ $widget_id ];
+		$widget = $wp_registered_widgets[ $widget_id ];
+		// Don't prepare the response body for HEAD requests.
+		if ( $request->is_method( 'HEAD' ) ) {
+			/** This filter is documented in wp-includes/rest-api/endpoints/class-wp-rest-widgets-controller.php */
+			return apply_filters( 'rest_prepare_widget', new WP_REST_Response( array() ), $widget, $request );
+		}
+
 		$parsed_id = wp_parse_widget_id( $widget_id );
 		$fields    = $this->get_fields_for_response( $request );