diff --git a/litellm/proxy/auth/user_api_key_auth.py b/litellm/proxy/auth/user_api_key_auth.py
index 9828311112e..5bba8e4e326 100644
--- a/litellm/proxy/auth/user_api_key_auth.py
+++ b/litellm/proxy/auth/user_api_key_auth.py
@@ -2459,7 +2459,11 @@ async def _run_centralized_common_checks(
     pass_through_endpoints: Final = general_settings.get("pass_through_endpoints", None)
     if pass_through_endpoints is not None:
         for endpoint in pass_through_endpoints:
-            if isinstance(endpoint, dict) and endpoint.get("path", "") == route and endpoint.get("auth") is not True:
+            if (
+                isinstance(endpoint, dict)
+                and endpoint.get("path", "") == route
+                and endpoint.get("auth", True) is not True
+            ):
                 return
 
     # No-auth dev mode: master_key unset AND no JWT/OAuth2 auth
diff --git a/litellm/proxy/pass_through_endpoints/pass_through_endpoints.py b/litellm/proxy/pass_through_endpoints/pass_through_endpoints.py
index ea4ede7e513..38becf465cf 100644
--- a/litellm/proxy/pass_through_endpoints/pass_through_endpoints.py
+++ b/litellm/proxy/pass_through_endpoints/pass_through_endpoints.py
@@ -3116,7 +3116,7 @@ async def _register_pass_through_endpoint(
     forward_headers: Final = endpoint_data.get("forward_headers")
     merge_query_params: Final = endpoint_data.get("merge_query_params")
     default_query_params: Final = endpoint_data.get("default_query_params")
-    auth: Final[bool | str | None] = endpoint_data.get("auth")
+    auth: Final[bool | str | None] = endpoint_data.get("auth", True)
     dependencies = None
     auth_enforced: Final = auth is not None and str(auth).lower() == "true"
 
diff --git a/tests/test_litellm/proxy/auth/test_user_api_key_auth.py b/tests/test_litellm/proxy/auth/test_user_api_key_auth.py
index 0cdbcde6abc..e4eb3c213a9 100644
--- a/tests/test_litellm/proxy/auth/test_user_api_key_auth.py
+++ b/tests/test_litellm/proxy/auth/test_user_api_key_auth.py
@@ -3960,6 +3960,50 @@ async def test_centralized_common_checks_runs_for_standard_auth():
             setattr(_proxy_server_mod, k, v)
 
 
+@pytest.mark.asyncio
+async def test_centralized_common_checks_runs_for_raw_passthrough_without_auth():
+    import litellm.proxy.proxy_server as _proxy_server_mod
+    from fastapi import Request
+    from starlette.datastructures import URL
+
+    route = "/chat/completions"
+    token = UserAPIKeyAuth(api_key="sk-test")
+    request = Request(scope={"type": "http", "headers": []})
+    request._url = URL(url=route)
+    attrs = _proxy_attrs_for_centralized_checks(user_custom_auth=None)
+    attrs["general_settings"] = {
+        "reject_clientside_metadata_tags": True,
+        "pass_through_endpoints": [
+            {
+                "path": route,
+                "target": "https://example.com",
+            }
+        ]
+    }
+    originals = {
+        attribute: getattr(_proxy_server_mod, attribute, None)
+        for attribute in attrs
+    }
+    try:
+        for attribute, value in attrs.items():
+            setattr(_proxy_server_mod, attribute, value)
+        with pytest.raises(ProxyException) as exc_info:
+            await _run_centralized_common_checks(
+                user_api_key_auth_obj=token,
+                request=request,
+                request_data={
+                    "model": "gpt-4o",
+                    "metadata": {"tags": ["client-supplied"]},
+                },
+                route=route,
+            )
+    finally:
+        for attribute, value in originals.items():
+            setattr(_proxy_server_mod, attribute, value)
+
+    assert exc_info.value.type == ProxyErrorTypes.bad_request_error
+
+
 @pytest.mark.asyncio
 @pytest.mark.parametrize(
     "route",
diff --git a/tests/test_litellm/proxy/pass_through_endpoints/test_passthrough_auth_default.py b/tests/test_litellm/proxy/pass_through_endpoints/test_passthrough_auth_default.py
index 44a75c362e5..3955def7eef 100644
--- a/tests/test_litellm/proxy/pass_through_endpoints/test_passthrough_auth_default.py
+++ b/tests/test_litellm/proxy/pass_through_endpoints/test_passthrough_auth_default.py
@@ -25,11 +25,12 @@ import pytest
 from fastapi import FastAPI
 
 
-from litellm.proxy._types import PassThroughGenericEndpoint
+from litellm.proxy._types import LiteLLMRoutes, PassThroughGenericEndpoint
 from litellm.proxy.auth.user_api_key_auth import (
     check_api_key_for_custom_headers_or_pass_through_endpoints,
 )
 from litellm.proxy.pass_through_endpoints.pass_through_endpoints import (
+    _registered_pass_through_routes,
     _register_pass_through_endpoint,
 )
 
@@ -79,6 +80,32 @@ async def test_register_passthrough_with_auth_true_works_for_oss(monkeypatch):
     )
 
 
+@pytest.mark.asyncio
+async def test_register_raw_passthrough_defaults_to_authentication():
+    path = "/raw-auth-default"
+    route_key = f"raw-auth-default:exact:{path}:GET"
+    endpoint: dict[str, object] = {
+        "id": "raw-auth-default",
+        "path": path,
+        "target": "https://example.com",
+        "methods": ["GET"],
+    }
+
+    try:
+        await _register_pass_through_endpoint(
+            endpoint=endpoint,
+            app=FastAPI(),
+            premium_user=False,
+            visited_endpoints=set(),
+        )
+        assert _registered_pass_through_routes[route_key]["auth"] is True
+        assert path in LiteLLMRoutes.openai_routes.value
+    finally:
+        _registered_pass_through_routes.pop(route_key, None)
+        if path in LiteLLMRoutes.openai_routes.value:
+            LiteLLMRoutes.openai_routes.value.remove(path)
+
+
 @pytest.mark.asyncio
 async def test_runtime_check_treats_missing_auth_key_as_authenticated():
     # The runtime dispatch in user_api_key_auth pulls