diff --git a/src/sentry/api/endpoints/user_notification_settings_options_detail.py b/src/sentry/api/endpoints/user_notification_settings_options_detail.py
index a35285814ba3f3..d74476ff438b5a 100644
--- a/src/sentry/api/endpoints/user_notification_settings_options_detail.py
+++ b/src/sentry/api/endpoints/user_notification_settings_options_detail.py
@@ -1,4 +1,5 @@
 from rest_framework import status
+from rest_framework.exceptions import NotFound
 from rest_framework.request import Request
 from rest_framework.response import Response
 
@@ -19,13 +20,26 @@ class UserNotificationSettingsOptionsDetailEndpoint(UserEndpoint):
     # TODO(Steve): Make not private when we launch new system
     private = True
 
-    def delete(self, request: Request, user: User, notification_option_id: str) -> Response:
+    def convert_args(
+        self,
+        request: Request,
+        user_id: int | str | None = None,
+        *args,
+        notification_option_id: int,
+        **kwargs,
+    ):
+        args, kwargs = super().convert_args(request, user_id, *args, **kwargs)
+        user = kwargs["user"]
         try:
-            option = NotificationSettingOption.objects.get(
-                id=notification_option_id,
-            )
+            option = NotificationSettingOption.objects.get(id=notification_option_id, user=user)
         except NotificationSettingOption.DoesNotExist:
-            return Response(status=status.HTTP_404_NOT_FOUND)
+            raise NotFound(detail="User notification setting does not exist")
 
-        option.delete()
+        kwargs["notification_setting_option"] = option
+        return args, kwargs
+
+    def delete(
+        self, request: Request, user: User, notification_setting_option: NotificationSettingOption
+    ) -> Response:
+        notification_setting_option.delete()
         return Response(status=status.HTTP_204_NO_CONTENT)
diff --git a/tests/sentry/api/endpoints/test_user_notification_settings_options_details.py b/tests/sentry/api/endpoints/test_user_notification_settings_options_details.py
index 785336f1633f8c..ff9dc10158df1c 100644
--- a/tests/sentry/api/endpoints/test_user_notification_settings_options_details.py
+++ b/tests/sentry/api/endpoints/test_user_notification_settings_options_details.py
@@ -24,18 +24,20 @@ def setUp(self):
         super().setUp()
         self.login_as(self.user)
 
-        option = NotificationSettingOption.objects.create(
+        self.option = NotificationSettingOption.objects.create(
             user_id=self.user.id,
             scope_type=NotificationScopeEnum.ORGANIZATION.value,
             scope_identifier=self.organization.id,
             type=NotificationSettingEnum.ISSUE_ALERTS.value,
             value=NotificationSettingsOptionEnum.ALWAYS.value,
         )
+
+    def test_simple(self):
         self.get_success_response(
             "me",
-            option.id,
+            self.option.id,
         )
-        assert not NotificationSettingOption.objects.filter(id=option.id).exists()
+        assert not NotificationSettingOption.objects.filter(id=self.option.id).exists()
 
     def test_invalid_option(self):
         self.get_error_response(
@@ -43,3 +45,22 @@ def test_invalid_option(self):
             "123",
             status_code=status.HTTP_404_NOT_FOUND,
         )
+
+    def test_cannot_delete_other_users_setting(self):
+        victim_user = self.create_user()
+        victim_org = self.create_organization(owner=victim_user)
+        victim_option = NotificationSettingOption.objects.create(
+            user_id=victim_user.id,
+            scope_type=NotificationScopeEnum.ORGANIZATION.value,
+            scope_identifier=victim_org.id,
+            type=NotificationSettingEnum.ISSUE_ALERTS.value,
+            value=NotificationSettingsOptionEnum.ALWAYS.value,
+        )
+
+        response = self.get_error_response(
+            "me",
+            victim_option.id,
+            status_code=status.HTTP_404_NOT_FOUND,
+        )
+        assert response.data["detail"] == "User notification setting does not exist"
+        assert NotificationSettingOption.objects.filter(id=victim_option.id).exists()