workaround

package.json

@@ -32,7 +32,8 @@
     "ts-node": "^10.9.1",
     "typescript": "^5.3.3",
     "vike": "^0.4.162",
-    "vite": "^5.0.10"
+    "vite": "^5.0.10",
+    "vite-plugin-cjs-interop": "^2.0.6"
   },
   "type": "module",
   "devDependencies": {

pages/index/+Page.tsx

@@ -1,4 +1,8 @@
 import ImageGallery from "react-image-gallery";
+/* Manual fix:
+import ImageGallery_  from "react-image-gallery";
+const ImageGallery = (ImageGallery_ as any).default as typeof ImageGallery_
+*/
 // import stylesheet if you're not already using CSS @import
 import "react-image-gallery/styles/css/image-gallery.css";
 
@@ -26,4 +30,4 @@ function Page() {
       <ImageGallery items={images} />;
     </>
   )
-}
+}

vite.config.ts

@@ -1,9 +1,29 @@
 import react from '@vitejs/plugin-react'
 import vike from 'vike/plugin'
-import { UserConfig } from 'vite'
+import {cjsInterop} from "vite-plugin-cjs-interop";
+import {UserConfig} from 'vite'
 
-const config: UserConfig = {
-  plugins: [react(), vike()]
-}
-
-export default config
+export default {
+  plugins: [
+    react(), vike(),
+    cjsInterop({
+      // List of CJS dependencies that require interop
+      dependencies: [
+        "react-image-gallery",
+      ],
+    }),
+  ],
+  /* Doesn't work:
+  ssr: {
+    noExternal: [
+         "react-image-gallery",
+    ],
+    // https://github.com/vitejs/vite/issues/14158#issuecomment-1685033558
+    optimizeDeps: {
+      include: [
+           "react-image-gallery",
+      ]
+    }
+  }
+  */
+} satisfies UserConfig;