[3.13] gh-144133: Add a warning to the `encodings.punycode` documentation (GH-151812...

(cherry picked from commit 7ec70e1df33098de24d4b2cb181586d04cdde441)

Co-authored-by: Stan Ulbrych <stan@python.org>

diff --git a/Doc/library/codecs.rst b/Doc/library/codecs.rst
index 8f3a4768c5efc2f4379ef53fe0fd5799e0ae67a6..e88992917573eae88eaa65923356e6bf052ce151 100644 (file)
--- a/Doc/library/codecs.rst
+++ b/Doc/library/codecs.rst
@@ -1385,6 +1385,14 @@ encodings.
 | punycode           |         | Implement :rfc:`3492`.    |
 |                    |         | Stateful codecs are not   |
 |                    |         | supported.                |
+|                    |         |                           |
+|                    |         | .. warning::              |
+|                    |         |                           |
+|                    |         |    The decoding and       |
+|                    |         |    encoding algorithms    |
+|                    |         |    scale poorly, so       |
+|                    |         |    limit the length of    |
+|                    |         |    untrusted input.       |
 +--------------------+---------+---------------------------+
 | raw_unicode_escape |         | Latin-1 encoding with     |
 |                    |         | :samp:`\\u{XXXX}` and     |