diff --git a/http/server/HttpHandler.cpp b/http/server/HttpHandler.cpp
index fa2013b32..cbbafc839 100644
--- a/http/server/HttpHandler.cpp
+++ b/http/server/HttpHandler.cpp
@@ -549,7 +549,7 @@ int HttpHandler::HandleHttpRequest() {
         }
     }
 
-    if (writer && writer->state != hv::HttpResponseWriter::SEND_BEGIN) {
+    if (writer && !writer->isBegin()) {
         status_code = HTTP_STATUS_NEXT;
     }
     if (status_code == HTTP_STATUS_NEXT) {
@@ -777,6 +777,18 @@ int HttpHandler::FeedRecvData(const char* data, size_t len) {
     case HttpHandler::HTTP_V1:
     case HttpHandler::HTTP_V2:
         if (state != WANT_RECV) {
+            // A new request arrived on this connection before the previous one
+            // finished. Reset() reuses the same req/resp objects, so if an async
+            // handler on another thread is still producing/sending the previous
+            // response (writer not yet End()ed), resetting here races that thread
+            // and can crash. In that case reject the pipelined/early data and let
+            // the caller close the connection. Otherwise (response already sent)
+            // it is safe to reset for the next keep-alive request.
+            if (writer && !writer->isEnd()) {
+                hloge("[%s:%d] new request while previous async response is still in flight", ip, port);
+                error = ERR_REQUEST;
+                return -1;
+            }
             Reset();
         }
         nfeed = parser->FeedRecvData(data, len);
diff --git a/http/server/HttpResponseWriter.h b/http/server/HttpResponseWriter.h
index 18636c58d..badd1cadd 100644
--- a/http/server/HttpResponseWriter.h
+++ b/http/server/HttpResponseWriter.h
@@ -34,6 +34,12 @@ class HV_EXPORT HttpResponseWriter : public SocketChannel {
 
     bool isHttp2() const { return (bool)submitHttp2Response; }
 
+    // isBegin(): nothing has been written yet (still at SEND_BEGIN).
+    // isEnd():   the response has been fully handed off, i.e. End() was called
+    //            (End() is the terminal call in every usage sequence below).
+    bool isBegin() const { return state == SEND_BEGIN; }
+    bool isEnd() const { return end == SEND_END; }
+
     // Begin -> End
     // Begin -> WriteResponse -> End
     // Begin -> WriteStatus -> WriteHeader -> WriteBody -> End