diff --git a/vllm/v1/engine/core.py b/vllm/v1/engine/core.py
index 0fa59579ee76..75e6f614fa3f 100644
--- a/vllm/v1/engine/core.py
+++ b/vllm/v1/engine/core.py
@@ -1043,6 +1043,7 @@ def run_engine_core(*args, dp_rank: int = 0, local_dp_rank: int = 0, **kwargs):
 
         engine_core: EngineCoreProc | None = None
         signal_callback: SignalCallback | None = None
+        exitcode = 0
         try:
             vllm_config: VllmConfig = kwargs["vllm_config"]
             parallel_config: ParallelConfig = vllm_config.parallel_config
@@ -1104,6 +1105,7 @@ def signal_handler(signum, frame):
             logger.debug("EngineCore exiting.")
             raise
         except Exception as e:
+            exitcode = 1
             if engine_core is None:
                 logger.exception("EngineCore failed to start.")
             else:
@@ -1117,6 +1119,12 @@ def signal_handler(signum, frame):
                 signal_callback.stop()
             if engine_core is not None:
                 engine_core.shutdown()
+            # Use os._exit() to terminate this subprocess immediately
+            # after cleanup. This skips Python's threading._shutdown()
+            # which can hang indefinitely when third-party libraries
+            # (e.g., httpx from huggingface-hub >= 1.7) create
+            # non-daemon background threads that block interpreter exit.
+            os._exit(exitcode)
 
     def _init_data_parallel(self, vllm_config: VllmConfig):
         pass