diff --git a/components/cast_streaming/browser/control/playback_command_dispatcher.cc b/components/cast_streaming/browser/control/playback_command_dispatcher.cc
index af3deceb75ba9..ab9fe1548a501 100644
--- a/components/cast_streaming/browser/control/playback_command_dispatcher.cc
+++ b/components/cast_streaming/browser/control/playback_command_dispatcher.cc
@@ -135,9 +135,13 @@ void PlaybackCommandDispatcher::OnRemotingSessionNegotiated(
       task_runner_, this,
       base::BindRepeating(&PlaybackCommandDispatcher::AcquireHandle,
                           base::Unretained(this)),
+      // SendRemotingRpcMessageToRemote is posted to |task_runner_| via
+      // PostDelayedTask in MessageProcessor::OnNoBuffersAvailable(), which can
+      // fire after |this| is destroyed. Bind to a WeakPtr so the posted task
+      // becomes a no-op once the dispatcher is gone.
       base::BindRepeating(
           &PlaybackCommandDispatcher::SendRemotingRpcMessageToRemote,
-          base::Unretained(this)));
+          weak_factory_.GetWeakPtr()));
 }
 
 void PlaybackCommandDispatcher::ConfigureRemotingAsync(
diff --git a/components/cast_streaming/browser/control/remoting/rpc_demuxer_stream_handler.cc b/components/cast_streaming/browser/control/remoting/rpc_demuxer_stream_handler.cc
index c6d6625f057ca..32d79f14f4a9f 100644
--- a/components/cast_streaming/browser/control/remoting/rpc_demuxer_stream_handler.cc
+++ b/components/cast_streaming/browser/control/remoting/rpc_demuxer_stream_handler.cc
@@ -305,9 +305,22 @@ void RpcDemuxerStreamHandler::MessageProcessor::OnNoBuffersAvailable() {
     remaining_time = base::Microseconds(0);
   }
 
+  // |process_message_cb_| may be (and in production is) bound via Unretained()
+  // to an object whose lifetime matches this MessageProcessor. Guard the posted
+  // task with this object's WeakPtr so it does not run after destruction.
   task_runner_->PostDelayedTask(
       FROM_HERE,
-      base::BindOnce(process_message_cb_, remote_handle(), std::move(message)),
+      base::BindOnce(
+          [](base::WeakPtr<MessageProcessor> self, RpcProcessMessageCB cb,
+             openscreen::cast::RpcMessenger::Handle handle,
+             std::unique_ptr<openscreen::cast::RpcMessage> message) {
+            if (!self) {
+              return;
+            }
+            cb.Run(handle, std::move(message));
+          },
+          weak_factory_.GetWeakPtr(), process_message_cb_, remote_handle(),
+          std::move(message)),
       remaining_time);
   last_request_time_ = now + remaining_time;