Also fix this setting false/0 from the frontend

* Fix: Hardening sweep, ensure a user is active, not just authenticated

* Missed this test

docs/usage.md

@@ -576,7 +576,9 @@ The following workflow action types are available:
 - Tags, correspondent, document type and storage path
 - Document owner
 - View and / or edit permissions to users or groups
-- Custom fields. Note that no value for the field will be set
+- Custom fields, optionally with a value. If no value is set, the field is only added to the
+  document and any value it may already have is left untouched. If a value is set, it will
+  overwrite an existing value of that field on the document.
 
 ##### Removal {#workflow-action-removal}
 

src-ui/src/app/components/common/input/custom-fields-values/custom-fields-values.component.spec.ts

@@ -52,10 +52,10 @@ describe('CustomFieldsValuesComponent', () => {
   })
 
   it('should set selectedFields and map values correctly', () => {
-    component.value = { 1: 'value1' }
-    component.selectedFields = [1, 2]
-    expect(component.selectedFields).toEqual([1, 2])
-    expect(component.value).toEqual({ 1: 'value1', 2: null })
+    component.value = { 1: 'value1', 3: 0, 4: false }
+    component.selectedFields = [1, 2, 3, 4]
+    expect(component.selectedFields).toEqual([1, 2, 3, 4])
+    expect(component.value).toEqual({ 1: 'value1', 2: null, 3: 0, 4: false })
   })
 
   it('should return the correct custom field by id', () => {

src-ui/src/app/components/common/input/custom-fields-values/custom-fields-values.component.ts

@@ -77,7 +77,7 @@ export class CustomFieldsValuesComponent extends AbstractInputComponent<Object>
     this._selectedFields = newFields
     // map the selected fields to an object with field_id as key and value as value
     this.value = newFields.reduce((acc, fieldId) => {
-      acc[fieldId] = this.value?.[fieldId] || null
+      acc[fieldId] = this.value?.[fieldId] ?? null
       return acc
     }, {})
     this.onChange(this.value)

src/documents/filters.py

@@ -1047,6 +1047,12 @@ class PermittedObjectsFilter(BaseFilterBackend):
     perm_codename: str | None = None
 
     def filter_queryset(self, request, queryset, view):
+        # Before the superuser and owner-only paths, neither of which consults
+        # permitted_object_ids. Scoped to authenticated users so anonymous
+        # access (AnonymousUser.is_active is False) keeps its existing
+        # unowned-only behaviour.
+        if request.user.is_authenticated and not request.user.is_active:
+            return queryset.none()
         if request.user.is_superuser:
             return queryset
         if not self.include_granted:

src/documents/permissions.py

@@ -54,11 +54,15 @@ class PaperlessObjectPermissions(DjangoObjectPermissions):
 
 class PaperlessAdminPermissions(BasePermission):
     def has_permission(self, request, view):
-        return request.user.is_staff
+        return request.user.is_active and request.user.is_staff
 
 
 def has_global_statistics_permission(user: User | None) -> bool:
-    if user is None or not getattr(user, "is_authenticated", False):
+    if (
+        user is None
+        or not getattr(user, "is_active", False)
+        or not getattr(user, "is_authenticated", False)
+    ):
         return False
 
     return getattr(user, "is_superuser", False) or user.has_perm(
@@ -67,7 +71,11 @@ def has_global_statistics_permission(user: User | None) -> bool:
 
 
 def has_system_status_permission(user: User | None) -> bool:
-    if user is None or not getattr(user, "is_authenticated", False):
+    if (
+        user is None
+        or not getattr(user, "is_active", False)
+        or not getattr(user, "is_authenticated", False)
+    ):
         return False
 
     return (
@@ -188,6 +196,13 @@ def permitted_object_ids(
     if user is None or not getattr(user, "is_authenticated", False):
         return base_qs.filter(owner__isnull=True).values_list("id", flat=True)
 
+    # Deactivated users get nothing, deactivated superusers included, so this
+    # has to come before the superuser shortcut. guardian's
+    # ObjectPermissionChecker denies inactive users, but get_objects_for_user
+    # (the pattern this replaces) does not, so it would not be inherited.
+    if not getattr(user, "is_active", False):
+        return base_qs.none().values_list("id", flat=True)
+
     if getattr(user, "is_superuser", False):
         return base_qs.values_list("id", flat=True)
 

src/documents/serialisers.py

@@ -3213,6 +3213,13 @@ class WorkflowActionSerializer(serializers.ModelSerializer[WorkflowAction]):
                         {"assign_title": f'Invalid f-string detected: "{e.args[0]}"'},
                     )
 
+        if attrs.get("assign_custom_fields_values"):
+            # Empty strings treated as None to avoid unexpected behavior
+            attrs["assign_custom_fields_values"] = {
+                field_id: (None if value == "" else value)
+                for field_id, value in attrs["assign_custom_fields_values"].items()
+            }
+
         if (
             "type" in attrs
             and attrs["type"] == WorkflowAction.WorkflowActionType.EMAIL

src/documents/tests/test_api_workflows.py

@@ -422,6 +422,11 @@ class TestApiWorkflows(DirectoriesMixin, APITestCase):
             json.dumps(
                 {
                     "assign_title": "",
+                    "assign_custom_fields": [self.cf1.id, self.cf2.id],
+                    "assign_custom_fields_values": {
+                        str(self.cf1.id): "",
+                        str(self.cf2.id): 0,
+                    },
                 },
             ),
             content_type="application/json",
@@ -429,6 +434,10 @@ class TestApiWorkflows(DirectoriesMixin, APITestCase):
         self.assertEqual(response.status_code, status.HTTP_201_CREATED)
         action = WorkflowAction.objects.get(id=response.data["id"])
         self.assertIsNone(action.assign_title)
+        self.assertEqual(
+            action.assign_custom_fields_values,
+            {str(self.cf1.id): None, str(self.cf2.id): 0},
+        )
 
         response = self.client.post(
             self.ENDPOINT_TRIGGERS,

src/documents/tests/test_permission_filtering_security.py

@@ -496,6 +496,28 @@ class TestPermittedObjectIdsGenericModels:
             expected_hidden=[strangers.pk],
         )
 
+    @pytest.mark.parametrize("is_superuser", [False, True])
+    def test_inactive_user_sees_nothing(self, model, factory, perm, is_superuser):
+        suffix = f"{model.__name__}_{is_superuser}"
+        user = User.objects.create_user(
+            username=f"inactive_{suffix}",
+            is_active=False,
+            is_superuser=is_superuser,
+        )
+        other = User.objects.create_user(username=f"other_{suffix}")
+        granted = factory(owner=other)
+        assign_perm(perm, user, granted)
+
+        assert_visible_document_ids(
+            permitted_object_ids(user, model, perm),
+            expected_visible=[],
+            expected_hidden=[
+                factory(owner=None).pk,
+                factory(owner=user).pk,
+                granted.pk,
+            ],
+        )
+
     def test_unowned_object_visible_to_everyone(self, model, factory, perm):
         user = User.objects.create_user(username=f"user_{model.__name__}")
         unowned = factory(owner=None)

src/documents/tests/test_permitted_objects_filter.py

@@ -68,3 +68,44 @@ class TestPermittedObjectsFilter:
         visible_ids = set(result.values_list("id", flat=True))
         assert visible_ids == {owned.pk}
         assert granted.pk not in visible_ids
+
+    @pytest.mark.parametrize(
+        ("username", "is_superuser"),
+        [("inactive", False), ("inactive_super", True)],
+    )
+    def test_inactive_user_sees_nothing(self, username: str, *, is_superuser: bool):
+        user = User.objects.create_user(
+            username=username,
+            is_active=False,
+            is_superuser=is_superuser,
+        )
+        TagFactory(owner=None)
+        TagFactory(owner=user)
+        granted = TagFactory(owner=User.objects.create_user(username=f"o_{username}"))
+        assign_perm("view_tag", user, granted)
+        request = APIRequestFactory().get("/")
+        request.user = user
+
+        result = PermittedObjectsFilter().filter_queryset(
+            request,
+            Tag.objects.all(),
+            _DummyView(),
+        )
+        assert result.count() == 0
+
+    def test_inactive_user_sees_nothing_with_include_granted_false(self):
+        user = User.objects.create_user(username="inactive_owner", is_active=False)
+        TagFactory(owner=user)
+        TagFactory(owner=None)
+        request = APIRequestFactory().get("/")
+        request.user = user
+
+        class _OwnerOnlyFilter(PermittedObjectsFilter):
+            include_granted = False
+
+        result = _OwnerOnlyFilter().filter_queryset(
+            request,
+            Tag.objects.all(),
+            _DummyView(),
+        )
+        assert result.count() == 0

src/documents/tests/test_workflows.py

@@ -2000,6 +2000,55 @@ class TestWorkflows(
                 r"Doc added in \w{3,}",
             )  # Match any 3-letter month name
 
+    def test_document_updated_workflow_existing_custom_field_empty_value(self) -> None:
+        """
+        GIVEN:
+            - Existing workflow with UPDATED trigger and action that assigns a custom field
+              with an empty value
+        WHEN:
+            - Document is updated that already contains the field with a value
+        THEN:
+            - The existing value is left untouched, see GH #13627
+        """
+        trigger = WorkflowTrigger.objects.create(
+            type=WorkflowTrigger.WorkflowTriggerType.DOCUMENT_UPDATED,
+            filter_has_document_type=self.dt,
+        )
+        action = WorkflowAction.objects.create()
+        action.assign_custom_fields.add(self.cf1)
+        action.assign_custom_fields_values = {self.cf1.pk: ""}
+        action.save()
+        w = Workflow.objects.create(
+            name="Workflow 1",
+            order=0,
+        )
+        w.triggers.add(trigger)
+        w.actions.add(action)
+        w.save()
+
+        doc = Document.objects.create(
+            title="sample test",
+            correspondent=self.c,
+            original_filename="sample.pdf",
+        )
+        CustomFieldInstance.objects.create(
+            document=doc,
+            field=self.cf1,
+            value_text="existing value",
+        )
+
+        superuser = User.objects.create_superuser("superuser")
+        self.client.force_authenticate(user=superuser)
+
+        self.client.patch(
+            f"/api/documents/{doc.id}/",
+            {"document_type": self.dt.id},
+            format="json",
+        )
+
+        doc.refresh_from_db()
+        self.assertEqual(doc.custom_fields.get(field=self.cf1).value, "existing value")
+
     def test_document_updated_workflow_existing_custom_field(self) -> None:
         """
         GIVEN:

src/documents/workflows/mutations.py

@@ -105,7 +105,8 @@ def apply_assignment_to_document(
                 field=field,
                 document=document,
             ).first()
-            if instance and args[value_field_name] is not None:
+            # empty string is indistinguishable from no value in the UI
+            if instance and args[value_field_name] not in (None, ""):
                 setattr(instance, value_field_name, args[value_field_name])
                 instance.save()
             elif not instance:

src/locale/en_US/LC_MESSAGES/django.po

@@ -2,7 +2,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: paperless-ngx\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2026-08-08 14:28+0000\n"
+"POT-Creation-Date: 2026-08-10 02:25+0000\n"
 "PO-Revision-Date: 2022-02-17 04:17\n"
 "Last-Translator: \n"
 "Language-Team: English\n"
@@ -53,7 +53,7 @@ msgstr ""
 msgid "Maximum nesting depth exceeded."
 msgstr ""
 
-#: documents/filters.py:1073
+#: documents/filters.py:1079
 msgid "Custom field not found"
 msgstr ""
 

src/paperless/auth.py

@@ -19,7 +19,10 @@ class AutoLoginMiddleware(MiddlewareMixin):
         if request.path.startswith("/api/token/") and request.method == "POST":
             return None
         try:
-            request.user = User.objects.get(username=settings.AUTO_LOGIN_USERNAME)
+            request.user = User.objects.get(
+                username=settings.AUTO_LOGIN_USERNAME,
+                is_active=True,
+            )
             auth.login(
                 request=request,
                 user=request.user,

src/paperless/tests/test_auth_middleware.py

@@ -0,0 +1,53 @@
+from django.contrib.auth.models import AnonymousUser
+from django.contrib.auth.models import User
+from django.test import RequestFactory
+from django.test import TestCase
+from django.test import override_settings
+
+from paperless.auth import AutoLoginMiddleware
+
+
+@override_settings(AUTO_LOGIN_USERNAME="autologin")
+class TestAutoLoginMiddleware(TestCase):
+    def setUp(self) -> None:
+        super().setUp()
+        self.factory = RequestFactory()
+        self.middleware = AutoLoginMiddleware(lambda request: None)
+
+    def _process(self, request):
+        # login() needs a session to write to
+        request.session = self.client.session
+        self.middleware.process_request(request)
+        return request
+
+    def test_active_user_is_logged_in(self) -> None:
+        """
+        GIVEN:
+            - AUTO_LOGIN_USERNAME names an active user
+        WHEN:
+            - A request is processed by the middleware
+        THEN:
+            - That user is attached to the request
+        """
+        user = User.objects.create_user(username="autologin")
+
+        request = self._process(self.factory.get("/"))
+
+        self.assertEqual(request.user, user)
+
+    def test_deactivated_user_is_not_logged_in(self) -> None:
+        """
+        GIVEN:
+            - AUTO_LOGIN_USERNAME names a user who has been deactivated
+        WHEN:
+            - A request is processed by the middleware
+        THEN:
+            - The request is left anonymous rather than authenticated as them
+        """
+        User.objects.create_user(username="autologin", is_active=False)
+
+        request = self.factory.get("/")
+        request.user = AnonymousUser()
+        self._process(request)
+
+        self.assertFalse(request.user.is_authenticated)