Merge branch 'main' into dev

# Conflicts:
#	docs/setup.md
#	src-ui/src/main.ts
#	src/documents/tests/test_api_bulk_edit.py
#	src/documents/tests/test_api_custom_fields.py
#	src/documents/tests/test_api_search.py
#	src/documents/tests/test_api_status.py
#	src/documents/tests/test_workflows.py
#	src/paperless_mail/tests/test_api.py

src/documents/serialisers.py

@@ -797,6 +797,25 @@ class ReadWriteSerializerMethodField(serializers.SerializerMethodField):
         return {self.field_name: data}
 
 
+def validate_documentlink_targets(user, doc_ids):
+    if Document.objects.filter(id__in=doc_ids).count() != len(doc_ids):
+        raise serializers.ValidationError(
+            "Some documents in value don't exist or were specified twice.",
+        )
+
+    if user is None:
+        return
+
+    target_documents = Document.objects.filter(id__in=doc_ids).select_related("owner")
+    if not all(
+        has_perms_owner_aware(user, "change_document", document)
+        for document in target_documents
+    ):
+        raise PermissionDenied(
+            _("Insufficient permissions."),
+        )
+
+
 class CustomFieldInstanceSerializer(serializers.ModelSerializer):
     field = serializers.PrimaryKeyRelatedField(queryset=CustomField.objects.all())
     value = ReadWriteSerializerMethodField(allow_null=True)
@@ -887,12 +906,11 @@ class CustomFieldInstanceSerializer(serializers.ModelSerializer):
                         "Value must be a list",
                     )
                 doc_ids = data["value"]
-                if Document.objects.filter(id__in=doc_ids).count() != len(
-                    data["value"],
-                ):
-                    raise serializers.ValidationError(
-                        "Some documents in value don't exist or were specified twice.",
-                    )
+                request = self.context.get("request")
+                validate_documentlink_targets(
+                    getattr(request, "user", None) if request is not None else None,
+                    doc_ids,
+                )
 
         return data
 
@@ -1713,6 +1731,19 @@ class BulkEditSerializer(
                 f"Some custom fields in {name} don't exist or were specified twice.",
             )
 
+        if isinstance(custom_fields, dict):
+            custom_field_map = CustomField.objects.in_bulk(ids)
+            for raw_field_id, value in custom_fields.items():
+                field = custom_field_map.get(int(raw_field_id))
+                if (
+                    field is not None
+                    and field.data_type == CustomField.FieldDataType.DOCUMENTLINK
+                    and value is not None
+                ):
+                    if not isinstance(value, list):
+                        raise serializers.ValidationError("Value must be a list")
+                    validate_documentlink_targets(self.user, value)
+
     def validate_method(self, method):
         if method == "set_correspondent":
             return bulk_edit.set_correspondent