fix(proxy): scope auth token cookie path to SERVER_ROOT_PATH

When SERVER_ROOT_PATH is set, the login token cookie was written with the
default path of "/", so deployments served under different root paths on the
same host (for example a.com and a.com/prefix) overwrote each other's auth
cookie and bounced users to /sso/key/generate. Set the cookie path to the
normalized server root path so cookies stay isolated per deployment.

litellm/proxy/management_endpoints/ui_sso.py

@@ -118,6 +118,7 @@ from litellm.proxy.management_endpoints.types import (
 from litellm.proxy.utils import (
     PrismaClient,
     ProxyLogging,
+    get_cookie_path_from_server_root_path,
     get_custom_url,
     get_server_root_path,
 )
@@ -3637,7 +3638,7 @@ class SSOAuthenticationHandler:
             litellm_dashboard_ui += "?login=success"
         verbose_proxy_logger.info("Redirecting to %s", litellm_dashboard_ui)
         redirect_response: Final = RedirectResponse(url=litellm_dashboard_ui, status_code=303)
-        redirect_response.set_cookie(key="token", value=jwt_token)
+        redirect_response.set_cookie(key="token", value=jwt_token, path=get_cookie_path_from_server_root_path())
         return redirect_response
 
     @staticmethod

litellm/proxy/proxy_server.py

@@ -605,6 +605,7 @@ from litellm.proxy.utils import (
     _is_valid_team_configs,
     evict_config_param,
     get_config_param,
+    get_cookie_path_from_server_root_path,
     get_custom_url,
     get_error_message_str,
     get_server_root_path,
@@ -14631,7 +14632,7 @@ async def login(request: Request):
 
     # Create redirect response with cookie
     redirect_response: Final = RedirectResponse(url=litellm_dashboard_ui, status_code=303)
-    redirect_response.set_cookie(key="token", value=jwt_token)
+    redirect_response.set_cookie(key="token", value=jwt_token, path=get_cookie_path_from_server_root_path())
     if cp_return_to:
         redirect_response.delete_cookie(key="litellm_cp_return_to")
     return redirect_response
@@ -14674,7 +14675,7 @@ async def login_v2(request: Request):
             content={"redirect_url": litellm_dashboard_ui, "token": jwt_token},
             status_code=status.HTTP_200_OK,
         )
-        json_response.set_cookie(key="token", value=jwt_token)
+        json_response.set_cookie(key="token", value=jwt_token, path=get_cookie_path_from_server_root_path())
         return json_response
     except Exception as e:
         verbose_proxy_logger.exception("litellm.proxy.proxy_server.login_v2(): Exception occurred - %s", e)
@@ -14819,7 +14820,7 @@ async def login_v3_exchange(request: Request):
             },
             status_code=status.HTTP_200_OK,
         )
-        json_response.set_cookie(key="token", value=cached_data["token"])
+        json_response.set_cookie(key="token", value=cached_data["token"], path=get_cookie_path_from_server_root_path())
         return json_response
     except ProxyException:
         raise

litellm/proxy/utils.py

@@ -6739,6 +6739,20 @@ def get_server_root_path() -> str:
     return os.getenv("SERVER_ROOT_PATH", "")
 
 
+def get_cookie_path_from_server_root_path() -> str:
+    """
+    Cookie `path` scoped to SERVER_ROOT_PATH.
+
+    Ensures auth cookies for deployments served under different root paths
+    (e.g. `a.com` vs `a.com/prefix`) do not overwrite each other. Defaults to
+    "/" when SERVER_ROOT_PATH is unset.
+    """
+    root_path = get_server_root_path()
+    if not root_path or root_path == "/":
+        return "/"
+    return "/" + root_path.strip("/")
+
+
 def normalize_route_for_root_path(route: str) -> str | None:
     """Strip SERVER_ROOT_PATH prefix. Returns de-prefixed route, or None if route is not under root path."""
     root_path: Final = get_server_root_path()

tests/test_litellm/proxy/test_proxy_utils.py

@@ -19,7 +19,7 @@ sys.path.insert(
 
 from unittest.mock import MagicMock, patch
 
-from litellm.proxy.utils import get_custom_url, join_paths
+from litellm.proxy.utils import get_cookie_path_from_server_root_path, get_custom_url, join_paths
 
 
 def test_get_custom_url(monkeypatch):
@@ -28,6 +28,26 @@ def test_get_custom_url(monkeypatch):
     assert custom_url == "http://0.0.0.0:4000/litellm/ui/"
 
 
+@pytest.mark.parametrize(
+    "server_root_path, expected",
+    [
+        (None, "/"),
+        ("", "/"),
+        ("/", "/"),
+        ("/litellm", "/litellm"),
+        ("litellm", "/litellm"),
+        ("/litellm/", "/litellm"),
+        ("/team/a", "/team/a"),
+    ],
+)
+def test_get_cookie_path_from_server_root_path(monkeypatch, server_root_path, expected):
+    if server_root_path is None:
+        monkeypatch.delenv("SERVER_ROOT_PATH", raising=False)
+    else:
+        monkeypatch.setenv("SERVER_ROOT_PATH", server_root_path)
+    assert get_cookie_path_from_server_root_path() == expected
+
+
 def test_proxy_only_error_true_for_llm_route():
     proxy_logging_obj = ProxyLogging(user_api_key_cache=DualCache())
     assert proxy_logging_obj._is_proxy_only_llm_api_error(