diff --git a/src/components/CloudLoader.tsx b/src/components/CloudLoader.tsx
index 6b82903..e3e399f 100644
--- a/src/components/CloudLoader.tsx
+++ b/src/components/CloudLoader.tsx
@@ -119,6 +119,14 @@ export function CloudLoader({ compact = false, variant = 'outline', className }:
       const response = await smartFetch(rawUrl);
       const buffer = await response.arrayBuffer();
 
+      // Valida tamanho + assinatura antes de converter
+      const sig = validateModelFile(fileName, buffer.byteLength, ext, buffer);
+      if (!sig.ok) {
+        toast.error(sig.reason!);
+        if (sig.detail) console.warn('[validateModelFile]', sig.detail);
+        return;
+      }
+
       let blob: Blob, outName = fileName, outSize = buffer.byteLength;
       if (ext === 'glb') {
         blob = new Blob([buffer], { type: 'model/gltf-binary' });