diff --git a/doc/arm/notes.rst b/doc/arm/notes.rst
index 00c8d5f8ed..25c1f5e84e 100644
--- a/doc/arm/notes.rst
+++ b/doc/arm/notes.rst
@@ -47,6 +47,7 @@ The list of known issues affecting the latest version in the 9.21 branch can be
 found at
 https://gitlab.isc.org/isc-projects/bind9/-/wikis/Known-Issues-in-BIND-9.21
 
+.. include:: ../notes/notes-9.21.11.rst
 .. include:: ../notes/notes-9.21.10.rst
 .. include:: ../notes/notes-9.21.9.rst
 .. include:: ../notes/notes-9.21.8.rst
diff --git a/doc/notes/notes-9.21.11.rst b/doc/notes/notes-9.21.11.rst
new file mode 100644
index 0000000000..9eb83388a4
--- /dev/null
+++ b/doc/notes/notes-9.21.11.rst
@@ -0,0 +1,138 @@
+.. Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+..
+.. SPDX-License-Identifier: MPL-2.0
+..
+.. This Source Code Form is subject to the terms of the Mozilla Public
+.. License, v. 2.0.  If a copy of the MPL was not distributed with this
+.. file, you can obtain one at https://mozilla.org/MPL/2.0/.
+..
+.. See the COPYRIGHT file distributed with this work for additional
+.. information regarding copyright ownership.
+
+Notes for BIND 9.21.11
+----------------------
+
+New Features
+~~~~~~~~~~~~
+
+- Support for parsing the DSYNC record has been added.
+
+  :gl:`#5440`
+
+Feature Changes
+~~~~~~~~~~~~~~~
+
+- Reword the 'shut down hung fetch while resolving' message.
+
+  The log message 'shut down hung fetch while resolving' may be
+  confusing because no detection of hung fetches actually takes place,
+  but rather the timer on the fetch context expires and the resolver
+  gives up.
+
+  Change the log message to actually say that instead of the original
+  cryptic message about hung fetch. :gl:`#3148`
+
+- Use native shared library extension.
+
+  Use the native shared library extension when build loadable libaries.
+  For most platforms this is ".so" but for Darwin it is ".dylib".
+  :gl:`#5375`
+
+- Plugin extension in plugin path is now optional.
+
+  Plugin configuration no longer requires the library file extension, so
+  it is now possible to invoke a plugin using the syntax `plugin query
+  "library"` instead of `plugin query "libary.so"`. :gl:`#5377`
+
+- Add deprecation warnings for RSASHA1, RSASHA1-NSEC3SHA1 and DS digest
+  type 1.
+
+  RSASHA1 and RSASHA1-NSEC-SHA1 DNSKEY algorithms have been deprecated
+  by the IETF and should no longer be used for DNSSEC. DS digest type 1
+  (SHA1) has also been deprecated. Validators are now expected to treat
+  these algorithms and digest as unknown, resulting in some zones being
+  treated as insecure when they were previously treated as secure.
+  Warnings have been added to named and tools when these algorithms and
+  this digest are being used for signing.
+
+  Zones signed with RSASHA1 or RSASHA1-NSEC-SHA1 should be migrated to a
+  different DNSKEY algorithm.
+
+  Zones with DS or CDS records with digest type 1 (SHA1) should be
+  updated to use a different digest type (e.g. SHA256) and the digest
+  type 1 records should be removed.
+
+  Related to #5358
+
+Bug Fixes
+~~~~~~~~~
+
+- Stale RRsets in a CNAME chain were not always refreshed.
+
+  With serve-stale enabled, a CNAME chain that contains a stale RRset,
+  the refresh query doesn't always properly refresh the stale RRsets.
+  This has been fixed. :gl:`#5243`
+
+- Add RPZ extended DNS error for zones with a CNAME override policy
+  configured.
+
+  When the zone is configured with a CNAME override policy, or the
+  response policy zone contains a wildcard CNAME, the extended DNS error
+  code was not added. This has been fixed. :gl:`#5342`
+
+- Fix cross builds.
+
+  Cross-compilation did not work even when the ``-Ddoc=disabled`` build
+  option was passed to Meson due to the build targets used for
+  generating documentation depending on a non-native executable. This
+  has been fixed. :gl:`#5379`
+
+- Fix named-makejournal man page installation.
+
+  The man page for :iscman:`named-makejournal` was erroneously not
+  installed when building from a source tarball. This has been fixed.
+  :gl:`#5379`
+
+- Fix plugin loading.
+
+  Loading plugins specified using just the shared library name (i.e.
+  without using an absolute path or a relative path) did not work. This
+  has been fixed. :gl:`#5379`
+
+- Fix dig issues.
+
+  When used with the ``+keepopen`` option with a TCP connection,
+  iscman:`dig` could terminate unexpectedly in rare situations.
+  Additionally, iscman:`dig` could hang and fail to shutdown properly
+  when interrupted during a query. These have been fixed. :gl:`#5381`
+
+- Log dropped or slipped responses in the query-errors category.
+
+  Responses which were dropped or slipped because of RRL (Response Rate
+  Limiting) were logged in the ``rate-limit`` category instead of the
+  ``query-errors`` category, as documented in ARM. This has been fixed.
+  :gl:`#5388`
+
+- Synth-from-dnssec was not working in some scenarios.
+
+  Aggressive use of DNSSEC-Validated cache with NSEC was not working in
+  scenarios when no parent NSEC was not in cache.  This has been fixed.
+  :gl:`#5422`
+
+- Clean enough memory when adding new ADB names/entries under memory
+  pressure.
+
+  The ADB memory cleaning is opportunistic even when we are under memory
+  pressure (in the overmem condition).  Split the opportunistic LRU
+  cleaning and overmem cleaning and make the overmem cleaning always
+  cleanup double of the newly allocated adbname/adbentry to ensure we
+  never allocate more memory than the assigned limit.
+
+- Prevent spurious validation failures.
+
+  Under rare circumstances, validation could fail if multiple clients
+  simultaneously iterated the same set of signatures.
+
+  References #3014
+
+