fix: multiple file upload issue

CHANGELOG.md

@@ -21,6 +21,7 @@ should change the heading of the (upcoming) version to include a major version b
 ## @rjsf/core
 
 - Updated `MultiSchemaField` to call the `onChange` handler after setting the new option, fixing [#3997](https://github.com/rjsf-team/react-jsonschema-form/issues/3977) and [#4314](https://github.com/rjsf-team/react-jsonschema-form/issues/4314)
+- Fix an issue where only the first file was uploaded when users selected multiple files for upload.
 
 ## @rjsf/utils
 

packages/core/src/components/widgets/FileWidget.tsx

@@ -169,7 +169,7 @@ function FileWidget<T = any, S extends StrictRJSFSchema = RJSFSchema, F extends
       processFiles(event.target.files).then((filesInfoEvent) => {
         const newValue = filesInfoEvent.map((fileInfo) => fileInfo.dataURL);
         if (multiple) {
-          onChange(value.concat(newValue[0]));
+          onChange(value.concat(newValue));
         } else {
           onChange(newValue[0]);
         }