diff --git a/addons/mail_plugin/tests/common.py b/addons/mail_plugin/tests/common.py
index 98e8fcaebf4..400c3e57498 100644
--- a/addons/mail_plugin/tests/common.py
+++ b/addons/mail_plugin/tests/common.py
@@ -8,6 +8,7 @@ from unittest.mock import patch
 from odoo.addons.mail.tests.common import mail_new_test_user
 from odoo.http import request
 from odoo.tests.common import HttpCase
+from odoo import SUPERUSER_ID
 
 
 @contextmanager
@@ -19,7 +20,7 @@ def mock_auth_method_outlook(login):
     :param login: Login of the user used for the authentication
     """
     def patched_auth_method_outlook(*args, **kwargs):
-        request.update_env(user=request.env['res.users'].search([('login', '=', login)], limit=1))
+        request.update_env(user=request.env['res.users'].with_user(SUPERUSER_ID).search([('login', '=', login)], limit=1))
 
     with patch(
             'odoo.addons.mail_plugin.models.ir_http.IrHttp'
diff --git a/addons/website/models/res_users.py b/addons/website/models/res_users.py
index 10ebc1499e8..f6ab17e03fe 100644
--- a/addons/website/models/res_users.py
+++ b/addons/website/models/res_users.py
@@ -60,7 +60,7 @@ class ResUsers(models.Model):
 
     @api.model
     def _get_signup_invitation_scope(self):
-        current_website = self.env['website'].get_current_website()
+        current_website = self.env['website'].sudo().get_current_website()
         return current_website.auth_signup_uninvited or super(ResUsers, self)._get_signup_invitation_scope()
 
     @classmethod
diff --git a/addons/website/models/website.py b/addons/website/models/website.py
index c0d95a79b58..7f268f7d004 100644
--- a/addons/website/models/website.py
+++ b/addons/website/models/website.py
@@ -975,7 +975,7 @@ class Website(models.Model):
 
         # The format of `httprequest.host` is `domain:port`
         domain_name = request and request.httprequest.host or ''
-        website_id = self._get_current_website_id(domain_name, fallback=fallback)
+        website_id = self.sudo()._get_current_website_id(domain_name, fallback=fallback)
         return self.browse(website_id)
 
     @tools.ormcache('domain_name', 'fallback')
diff --git a/odoo/addons/base/models/ir_http.py b/odoo/addons/base/models/ir_http.py
index d5ab635a5f0..96706f90ab3 100644
--- a/odoo/addons/base/models/ir_http.py
+++ b/odoo/addons/base/models/ir_http.py
@@ -183,7 +183,8 @@ class IrHttp(models.AbstractModel):
         # verify the default language set in the context is valid,
         # otherwise fallback on the company lang, english or the first
         # lang installed
-        request.update_context(lang=get_lang(request.env)._get_cached('code'))
+        env = request.env if request.env.uid else request.env['base'].with_user(SUPERUSER_ID).env
+        request.update_context(lang=get_lang(env)._get_cached('code'))
 
     @classmethod
     def _dispatch(cls, endpoint):
diff --git a/odoo/addons/base/models/ir_qweb.py b/odoo/addons/base/models/ir_qweb.py
index 91a179b1c9f..71a17884eec 100644
--- a/odoo/addons/base/models/ir_qweb.py
+++ b/odoo/addons/base/models/ir_qweb.py
@@ -2425,7 +2425,7 @@ class IrQWeb(models.AbstractModel):
         If debug=assets, the assets will be regenerated when a file which composes them has been modified.
         Else, the assets will be generated only once and then stored in cache.
         """
-        rtl = self.env['res.lang']._lang_get_direction(self.env.context.get('lang') or self.env.user.lang) == 'rtl'
+        rtl = self.env['res.lang'].sudo()._lang_get_direction(self.env.context.get('lang') or self.env.user.lang) == 'rtl'
         assets_params = self.env['ir.asset']._get_asset_params() # website_id
         debug_assets = debug and 'assets' in debug