--- a/hooks/security.py	Mon Jun 15 10:46:49 2015 +0200
+++ b/hooks/security.py	Mon Jun 15 10:49:33 2015 +0200
@@ -136,6 +136,19 @@
         self.entity.cw_check_perm('delete')
 
 
+def skip_inlined_relation_security(cnx, rschema, eid):
+    """return True if security for the given inlined relation should be skipped,
+    in case where the relation has been set through modification of
+    `entity.cw_edited` in a hook
+    """
+    assert rschema.inlined
+    try:
+        entity = cnx.transaction_data['ecache'][eid]
+    except KeyError:
+        return False
+    return rschema.type in entity.cw_edited.skip_security
+
+
 class BeforeAddRelationSecurityHook(SecurityHook):
     __regid__ = 'securitybeforeaddrelation'
     events = ('before_add_relation',)
@@ -146,6 +159,9 @@
             if (self.eidfrom, self.rtype, self.eidto) in nocheck:
                 return
             rschema = self._cw.repo.schema[self.rtype]
+            if rschema.inlined and skip_inlined_relation_security(
+                    self._cw, rschema, self.eidfrom):
+                return
             rdef = rschema.rdef(self._cw.entity_metas(self.eidfrom)['type'],
                                 self._cw.entity_metas(self.eidto)['type'])
             rdef.check_perm(self._cw, 'add', fromeid=self.eidfrom, toeid=self.eidto)
@@ -156,11 +172,14 @@
     events = ('after_add_relation',)
 
     def __call__(self):
-        if not self.rtype in BEFORE_ADD_RELATIONS:
+        if self.rtype not in BEFORE_ADD_RELATIONS:
             nocheck = self._cw.transaction_data.get('skip-security', ())
             if (self.eidfrom, self.rtype, self.eidto) in nocheck:
                 return
             rschema = self._cw.repo.schema[self.rtype]
+            if rschema.inlined and skip_inlined_relation_security(
+                    self._cw, rschema, self.eidfrom):
+                return
             if self.rtype in ON_COMMIT_ADD_RELATIONS:
                 CheckRelationPermissionOp.get_instance(self._cw).add_data(
                     ('add', rschema, self.eidfrom, self.eidto) )
@@ -179,6 +198,9 @@
         if (self.eidfrom, self.rtype, self.eidto) in nocheck:
             return
         rschema = self._cw.repo.schema[self.rtype]
+        if rschema.inlined and skip_inlined_relation_security(
+                self._cw, rschema, self.eidfrom):
+            return
         rdef = rschema.rdef(self._cw.entity_metas(self.eidfrom)['type'],
                             self._cw.entity_metas(self.eidto)['type'])
         rdef.check_perm(self._cw, 'delete', fromeid=self.eidfrom, toeid=self.eidto)

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hooks/test/unittest_security.py	Mon Jun 15 10:49:33 2015 +0200
@@ -0,0 +1,56 @@
+# copyright 2015 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
+# contact http://www.logilab.fr/ -- mailto:contact@logilab.fr
+#
+# This file is part of CubicWeb.
+#
+# CubicWeb is free software: you can redistribute it and/or modify it under the
+# terms of the GNU Lesser General Public License as published by the Free
+# Software Foundation, either version 2.1 of the License, or (at your option)
+# any later version.
+#
+# CubicWeb is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+# FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Lesser General Public License along
+# with CubicWeb.  If not, see <http://www.gnu.org/licenses/>.
+
+from cubicweb.devtools.testlib import CubicWebTC
+from cubicweb.server import hook
+from cubicweb.predicates import is_instance
+
+
+class SecurityHooksTC(CubicWebTC):
+    def setup_database(self):
+        with self.admin_access.repo_cnx() as cnx:
+            self.add_eid = cnx.create_entity('EmailAddress',
+                                             address=u'hop@perdu.com',
+                                             reverse_use_email=cnx.user.eid).eid
+            cnx.commit()
+
+    def test_inlined_cw_edited_relation(self):
+        """modification of cw_edited to add an inlined relation shouldn't trigger a security error.
+
+        Test for https://www.cubicweb.org/ticket/5477315
+        """
+        sender = self.repo.schema['Email'].rdef('sender')
+        with self.temporary_permissions((sender, {'add': ()})):
+
+            class MyHook(hook.Hook):
+                __regid__ = 'test.pouet'
+                __select__ = hook.Hook.__select__ & is_instance('Email')
+                events = ('before_add_entity',)
+
+                def __call__(self):
+                    self.entity.cw_edited['sender'] = self._cw.user.primary_email[0].eid
+
+            with self.temporary_appobjects(MyHook):
+                with self.admin_access.repo_cnx() as cnx:
+                    email = cnx.create_entity('Email', messageid=u'1234')
+                    cnx.commit()
+                    self.assertEqual(email.sender[0].eid, self.add_eid)
+
+if __name__ == '__main__':
+    from logilab.common.testlib import unittest_main
+    unittest_main()