diff --git a/app/src/main/cpp/include/sion.h b/app/src/main/cpp/include/sion.h
index ebe5715..342f395 100644
--- a/app/src/main/cpp/include/sion.h
+++ b/app/src/main/cpp/include/sion.h
@@ -454,7 +454,9 @@ namespace sion {
     private:
         size_t resp_body_start_pos_ = -1;
 
-        String Sourse2Str() { return source_.size() == 0 ? "" : std::string(source_.data(), 0, source_.size()); }
+        String Sourse2Str() {
+            return (source_.size() <= 0 || source_.size() >= (1024 * 1024 * 1024)) ? "" : std::string(source_.data(), 0, source_.size());
+        }
 
         bool CanParseHeader() {
             auto buf_str = Sourse2Str();