diff --git a/.changes/next-release/bugfix-AWSCRTAsyncHTTPClient-a045823.json b/.changes/next-release/bugfix-AWSCRTAsyncHTTPClient-a045823.json
new file mode 100644
index 000000000000..f54b5fa0302e
--- /dev/null
+++ b/.changes/next-release/bugfix-AWSCRTAsyncHTTPClient-a045823.json
@@ -0,0 +1,6 @@
+{
+    "type": "bugfix",
+    "category": "AWS CRT Async HTTP Client",
+    "contributor": "",
+    "description": "Fixed potential connection leak issue when SDK failed to convert the SDK request to CRT request"
+}
diff --git a/.changes/next-release/bugfix-AWSCRTHTTPAsyncClient-88e9d07.json b/.changes/next-release/bugfix-AWSCRTHTTPAsyncClient-88e9d07.json
new file mode 100644
index 000000000000..7ad23e59bb11
--- /dev/null
+++ b/.changes/next-release/bugfix-AWSCRTHTTPAsyncClient-88e9d07.json
@@ -0,0 +1,6 @@
+{
+    "type": "bugfix",
+    "category": "AWS CRT Async HTTP Client",
+    "contributor": "",
+    "description": "Fixed the issue where AWS CRT HTTP client was eagerly buffering data before the underlying CRT component was able to handle it"
+}
diff --git a/http-clients/aws-crt-client/src/main/java/software/amazon/awssdk/http/crt/internal/CrtAsyncRequestExecutor.java b/http-clients/aws-crt-client/src/main/java/software/amazon/awssdk/http/crt/internal/CrtAsyncRequestExecutor.java
index 4db35956e8d4..4ede09d7ee3e 100644
--- a/http-clients/aws-crt-client/src/main/java/software/amazon/awssdk/http/crt/internal/CrtAsyncRequestExecutor.java
+++ b/http-clients/aws-crt-client/src/main/java/software/amazon/awssdk/http/crt/internal/CrtAsyncRequestExecutor.java
@@ -88,12 +88,12 @@ private void executeRequest(CrtAsyncRequestContext executionContext,
                                 CompletableFuture<Void> requestFuture,
                                 HttpClientConnection crtConn,
                                 AsyncExecuteRequest asyncRequest) {
-        HttpRequest crtRequest = CrtRequestAdapter.toAsyncCrtRequest(executionContext);
-        HttpStreamResponseHandler crtResponseHandler =
-            CrtResponseAdapter.toCrtResponseHandler(crtConn, requestFuture, asyncRequest.responseHandler());
-
         // Submit the request on the connection
         try {
+            HttpRequest crtRequest = CrtRequestAdapter.toAsyncCrtRequest(executionContext);
+            HttpStreamResponseHandler crtResponseHandler =
+                CrtResponseAdapter.toCrtResponseHandler(crtConn, requestFuture, asyncRequest.responseHandler());
+
             crtConn.makeRequest(crtRequest, crtResponseHandler).activate();
         } catch (HttpException e) {
             Throwable toThrow = wrapWithIoExceptionIfRetryable(e);
diff --git a/http-clients/aws-crt-client/src/main/java/software/amazon/awssdk/http/crt/internal/request/CrtRequestBodyAdapter.java b/http-clients/aws-crt-client/src/main/java/software/amazon/awssdk/http/crt/internal/request/CrtRequestBodyAdapter.java
index 79ee03ad5067..6fa64d8a011d 100644
--- a/http-clients/aws-crt-client/src/main/java/software/amazon/awssdk/http/crt/internal/request/CrtRequestBodyAdapter.java
+++ b/http-clients/aws-crt-client/src/main/java/software/amazon/awssdk/http/crt/internal/request/CrtRequestBodyAdapter.java
@@ -16,6 +16,7 @@
 package software.amazon.awssdk.http.crt.internal.request;
 
 import java.nio.ByteBuffer;
+import java.util.concurrent.atomic.AtomicBoolean;
 import software.amazon.awssdk.annotations.SdkInternalApi;
 import software.amazon.awssdk.crt.http.HttpRequestBodyStream;
 import software.amazon.awssdk.http.async.SdkHttpContentPublisher;
@@ -26,15 +27,19 @@
 final class CrtRequestBodyAdapter implements HttpRequestBodyStream {
     private final SdkHttpContentPublisher requestPublisher;
     private final ByteBufferStoringSubscriber requestBodySubscriber;
+    private final AtomicBoolean subscribed = new AtomicBoolean(false);
 
     CrtRequestBodyAdapter(SdkHttpContentPublisher requestPublisher, long readLimit) {
         this.requestPublisher = requestPublisher;
         this.requestBodySubscriber = new ByteBufferStoringSubscriber(readLimit);
-        requestPublisher.subscribe(requestBodySubscriber);
     }
 
     @Override
     public boolean sendRequestBody(ByteBuffer bodyBytesOut) {
+        if (subscribed.compareAndSet(false, true)) {
+            requestPublisher.subscribe(requestBodySubscriber);
+        }
+
         return requestBodySubscriber.transferTo(bodyBytesOut) == TransferResult.END_OF_STREAM;
     }
 
diff --git a/http-clients/aws-crt-client/src/test/java/software/amazon/awssdk/http/crt/internal/CrtAsyncRequestExecutorTest.java b/http-clients/aws-crt-client/src/test/java/software/amazon/awssdk/http/crt/internal/CrtAsyncRequestExecutorTest.java
index a83bd27ec2e6..feaf9db3d472 100644
--- a/http-clients/aws-crt-client/src/test/java/software/amazon/awssdk/http/crt/internal/CrtAsyncRequestExecutorTest.java
+++ b/http-clients/aws-crt-client/src/test/java/software/amazon/awssdk/http/crt/internal/CrtAsyncRequestExecutorTest.java
@@ -105,6 +105,29 @@ public void acquireConnectionThrowException_shouldInvokeOnError() {
         assertThat(executeFuture).hasFailedWithThrowableThat().hasCause(exception).isInstanceOf(IOException.class);
     }
 
+    @Test
+    public void invalidRequest_requestConversionThrowError_shouldInvokeOnError() {
+        CrtAsyncRequestContext context = CrtAsyncRequestContext.builder()
+                                                               .crtConnPool(connectionManager)
+                                                               .request(AsyncExecuteRequest.builder()
+                                                                                           .responseHandler(responseHandler)
+                                                                                           .build())
+                                                               .build();
+        CompletableFuture<HttpClientConnection> completableFuture = new CompletableFuture<>();
+
+        Mockito.when(connectionManager.acquireConnection()).thenReturn(completableFuture);
+        completableFuture.complete(httpClientConnection);
+
+        CompletableFuture<Void> executeFuture = requestExecutor.execute(context);
+
+        ArgumentCaptor<Exception> argumentCaptor = ArgumentCaptor.forClass(Exception.class);
+        Mockito.verify(responseHandler).onError(argumentCaptor.capture());
+
+        Exception actualException = argumentCaptor.getValue();
+        assertThat(actualException).isInstanceOf(NullPointerException.class);
+        assertThat(executeFuture).hasFailedWithThrowableThat().isInstanceOf(NullPointerException.class);
+    }
+
     @Test
     public void executeAsyncRequest_CrtRuntimeException_shouldInvokeOnError() {
         CrtRuntimeException exception = new CrtRuntimeException("");