diff --git a/superset/security/api.py b/superset/security/api.py
index bb8995d4665..92084a25ced 100644
--- a/superset/security/api.py
+++ b/superset/security/api.py
@@ -40,6 +40,7 @@ from superset.commands.dashboard.embedded.exceptions import (
     EmbeddedDashboardNotFoundError,
 )
 from superset.commands.exceptions import ForbiddenError
+from superset.constants import RouteMethod
 from superset.exceptions import SupersetGenericErrorException
 from superset.extensions import db, event_logger
 from superset.security.guest_token import (
@@ -423,6 +424,11 @@ class UserRegistrationsRestAPI(BaseSupersetModelRestApi):
     resource_name = "security/user_registrations"
     datamodel = SQLAInterface(RegisterUser)
     allow_browser_login = True
+    # This API is read-only by design: restricting the exposed routes keeps
+    # the FAB default POST/PUT/DELETE handlers from ever being registered,
+    # so a mis-granted role cannot create, alter, or silently cancel a
+    # pending registration.
+    include_route_methods = {RouteMethod.GET, RouteMethod.GET_LIST, RouteMethod.INFO}
     # NOTE: registration_hash is intentionally excluded from both list_columns
     # and search_columns. It is a bearer token for the
     # /register/activation/<hash> flow; exposing it in API responses (and thus
diff --git a/superset/security/manager.py b/superset/security/manager.py
index 79c262dfddc..21f0729d410 100644
--- a/superset/security/manager.py
+++ b/superset/security/manager.py
@@ -1432,6 +1432,10 @@ class SupersetSecurityManager(  # pylint: disable=too-many-public-methods
         "Security",
         "SQL Lab",
         "User Registrations",
+        # REST counterpart of the FAB "User Registrations" views. FAB derives
+        # the view-menu name from the class name; without this entry
+        # _is_gamma_pvm grants its permissions to stock Gamma and Alpha.
+        "UserRegistrationsRestAPI",
         "User's Statistics",
         # Guarding all AB_ADD_SECURITY_API = True REST APIs
         "RoleRestAPI",
diff --git a/tests/unit_tests/security/api_test.py b/tests/unit_tests/security/api_test.py
index f2962a82a66..ad3c3c1e2eb 100644
--- a/tests/unit_tests/security/api_test.py
+++ b/tests/unit_tests/security/api_test.py
@@ -19,8 +19,10 @@ from typing import Any
 import pytest
 from marshmallow import ValidationError
 
+from superset.constants import RouteMethod
 from superset.extensions import csrf
-from superset.security.api import RlsRuleSchema
+from superset.security.api import RlsRuleSchema, UserRegistrationsRestAPI
+from superset.security.manager import SupersetSecurityManager
 
 
 @pytest.mark.parametrize(
@@ -172,3 +174,26 @@ def test_rls_rule_schema_rejects_falsy_dataset(dataset: Any) -> None:
     with pytest.raises(ValidationError) as exc_info:
         RlsRuleSchema().load({"dataset": dataset, "clause": "tenant_id = 1"})
     assert "dataset" in exc_info.value.messages
+
+
+def test_user_registrations_rest_api_is_admin_only() -> None:
+    """
+    The API is documented Admin-only, but the admin gate is membership in
+    ADMIN_ONLY_VIEW_MENUS keyed by the FAB-derived view-menu name (the class
+    name). If the entry is missing, ``superset init`` grants the API's
+    permissions to stock Gamma and Alpha via ``_is_gamma_pvm``, exposing
+    pending registrants' PII and registration deletion.
+    """
+    assert "UserRegistrationsRestAPI" in SupersetSecurityManager.ADMIN_ONLY_VIEW_MENUS
+
+
+def test_user_registrations_rest_api_routes_are_read_only() -> None:
+    """
+    Only the read routes should be registered; the FAB default POST/PUT/
+    DELETE handlers must not exist on this API at all.
+    """
+    assert UserRegistrationsRestAPI.include_route_methods == {
+        RouteMethod.GET,
+        RouteMethod.GET_LIST,
+        RouteMethod.INFO,
+    }