diff --git a/Doc/whatsnew/3.10.rst b/Doc/whatsnew/3.10.rst
index 570af7f..2697cf9 100644
--- a/Doc/whatsnew/3.10.rst
+++ b/Doc/whatsnew/3.10.rst
@@ -1337,6 +1337,13 @@
 documentation.
 (Contributed by Adam Goldschmidt, Senthil Kumaran and Ken Jin in :issue:`42967`.)
 
+The presence of newline or tab characters in parts of a URL allows for some
+forms of attacks. Following the WHATWG specification that updates :rfc:`3986`,
+ASCII newline ``\n``, ``\r`` and tab ``\t`` characters are stripped from the
+URL by the parser in :mod:`urllib.parse` preventing such attacks. The removal
+characters are controlled by a new module level variable
+``urllib.parse._UNSAFE_URL_BYTES_TO_REMOVE``. (See :issue:`43882`)
+
 xml
 ---