doc: add known issue to v24.11.0 release notes

PR-URL: #60467
Refs: nodejs/nodejs.org#8280
Reviewed-By: Zeyu "Alex" Yang <himself65@outlook.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Filip Skokan <panva.ip@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Mohammed Keyvanzadeh <mohammadkeyvanzade94@gmail.com>

Author: richardlau

doc/changelogs/CHANGELOG_V24.md

@@ -70,6 +70,15 @@ the end of April 2028.
 Other than updating metadata, such as the `process.release` object, to reflect
 that the release is LTS, no further changes from Node.js 24.10.0 are included.
 
+### Known issue
+
+An issue has been identified in the Node.js 24.x line with `Buffer.allocUnsafe`
+unintentionally returning zero-filled buffers. This API is
+[documented to return uninitialized memory](https://nodejs.org/docs/latest-v24.x/api/buffer.html#static-method-bufferallocunsafesize).
+The documented behavior will be restored in the next Node.js 24.x LTS release to bring
+it back in line with previous releases. For more information, see
+[#60423](https://github.com/nodejs/node/issues/60423).
+
 <a id="24.10.0"></a>
 
 ## 2025-10-08, Version 24.10.0 (Current), @RafaelGSS