Ticket #43757: 43757.3.diff

src/wp-includes/rest-api/endpoints/class-wp-rest-attachments-controller.php

@@ -122 +122 @@
                 $type = $file['type'];
                 $file = $file['file'];
 
+                /** Require the image processing functions. */
+                require_once ABSPATH . 'wp-admin/includes/image.php';
+
                 // use image exif/iptc data for title and caption defaults if possible
                 $image_meta = wp_read_image_metadata( $file );