Remove default value for data in Nested._deserialize (#2803)

sloria · web-flow · commit 7d15bae7cb55 · 2025-01-31T02:57:00.000Z
* Remove default value for data in Nested._deserialize

* Update changelog
diff --git a/CHANGELOG.rst b/CHANGELOG.rst
@@ -1,6 +1,15 @@
 Changelog
 ---------
 
+(unreleased)
+************
+
+Other changes:
+
+- Remove default value for the ``data`` param of `Nested._deserialize <marshmallow.fields.Nested._deserialize>` (:issue:`2802`).
+  Thanks :user:`gbenson` for reporting.
+
+
 3.26.0 (2025-01-22)
 *******************
 
diff --git a/src/marshmallow/fields.py b/src/marshmallow/fields.py
@@ -675,7 +675,7 @@ def _deserialize(
         self,
         value: typing.Any,
         attr: str | None,
-        data: typing.Mapping[str, typing.Any] | None = None,
+        data: typing.Mapping[str, typing.Any] | None,
         partial: bool | types.StrSequenceOrSet | None = None,
         **kwargs,
     ) -> typing.Any:
