diff --git a/apps/desktop-shell/scripts/check-config.mjs b/apps/desktop-shell/scripts/check-config.mjs
index cccc5087b..af15eb823 100644
--- a/apps/desktop-shell/scripts/check-config.mjs
+++ b/apps/desktop-shell/scripts/check-config.mjs
@@ -2294,6 +2294,17 @@ assertSameList(
   requiredRustHostModules,
   'desktop shell Rust bridge modules',
 );
+const desktopExportImagePayloadBody = extractFunctionBody(
+  desktopHostBridgeFilesSource,
+  'export_image_payload',
+);
+if (
+  !desktopExportImagePayloadBody.includes(
+    'bytes.is_empty() || bytes.len() > EXPORT_IMAGE_MAX_BYTES',
+  )
+) {
+  throw new Error('desktop shell image export must reject empty and oversized bytes');
+}
 assertSameList(
   extractNativeAppTauriInvokeCommands(nativeAppHostBridgeSource),
   ['HOST_BRIDGE_TAURI_COMMAND'],
diff --git a/apps/desktop-shell/src-tauri/src/host_bridge/files.rs b/apps/desktop-shell/src-tauri/src/host_bridge/files.rs
index 2d44cb81e..9dc06b73d 100644
--- a/apps/desktop-shell/src-tauri/src/host_bridge/files.rs
+++ b/apps/desktop-shell/src-tauri/src/host_bridge/files.rs
@@ -392,7 +392,7 @@ pub(crate) fn export_image_payload(
             "base64Data is invalid",
         )
     })?;
-    if bytes.len() > EXPORT_IMAGE_MAX_BYTES {
+    if bytes.is_empty() || bytes.len() > EXPORT_IMAGE_MAX_BYTES {
         return Err(failed(
             request.id.clone(),
             "invalid_request",
@@ -1272,6 +1272,15 @@ mod tests {
             "base64Data is invalid"
         );
 
+        let mut empty = request("file.exportImage");
+        empty.payload = Some(json!({
+            "fileName": "分享卡.png",
+            "base64Data": "",
+            "mimeType": "image/png"
+        }));
+        let response = export_image_payload(&empty).expect_err("empty image");
+        assert_eq!(response.error.expect("error").code, "invalid_request");
+
         let mut mismatched = request("file.exportImage");
         mismatched.payload = Some(json!({
             "fileName": "分享卡.png",