diff --git a/.github/actions/render/action.yml b/.github/actions/render/action.yml
index 5f20e428..31e1de30 100644
--- a/.github/actions/render/action.yml
+++ b/.github/actions/render/action.yml
@@ -6,7 +6,7 @@ inputs:
     default: 'master'
   DITA_OT_VERSION:
     description: 'DITA-OT version used for rendering'
-    default: '4.2.1'
+    default: '4.2.2'
 runs:
   using: 'composite'
   steps:
diff --git a/.github/workflows/gradle-wrapper-validation.yml b/.github/workflows/gradle-wrapper-validation.yml
index 3294a867..616013de 100644
--- a/.github/workflows/gradle-wrapper-validation.yml
+++ b/.github/workflows/gradle-wrapper-validation.yml
@@ -10,4 +10,4 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - uses: gradle/wrapper-validation-action@v2
+      - uses: gradle/wrapper-validation-action@v3
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 4a8fa94b..9a21ecb0 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -17,7 +17,7 @@ jobs:
     runs-on: ubuntu-latest
     env:
       WEBSITE_PLUGIN_BRANCH: 'master'
-      DITA_OT_VERSION: '4.2.1'
+      DITA_OT_VERSION: '4.2.2'
     steps:
       - name: Parse arguments
         run: |
diff --git a/package-lock.json b/package-lock.json
index d47fa37d..4c9c8a70 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -7,7 +7,7 @@
       "name": "docs",
       "license": "Apache-2.0",
       "devDependencies": {
-        "@prettier/plugin-xml": "3.3.1",
+        "@prettier/plugin-xml": "3.4.1",
         "husky": "^9.0.11",
         "lint-staged": "15.2.2",
         "prettier": "3.2.5",
@@ -235,9 +235,9 @@
       }
     },
     "node_modules/@prettier/plugin-xml": {
-      "version": "3.3.1",
-      "resolved": "https://registry.npmjs.org/@prettier/plugin-xml/-/plugin-xml-3.3.1.tgz",
-      "integrity": "sha512-kllNJk6n2pXJjGWdj+HAr1GhOoOTrlmeWkDYCGBzkyZS2l0K6h2gsUQcVif2cNqAE1MNC+nUrzN6QwEsCukPnQ==",
+      "version": "3.4.1",
+      "resolved": "https://registry.npmjs.org/@prettier/plugin-xml/-/plugin-xml-3.4.1.tgz",
+      "integrity": "sha512-Uf/6/+9ez6z/IvZErgobZ2G9n1ybxF5BhCd7eMcKqfoWuOzzNUxBipNo3QAP8kRC1VD18TIo84no7LhqtyDcTg==",
       "dev": true,
       "dependencies": {
         "@xml-tools/parser": "^1.0.11"
@@ -2916,9 +2916,9 @@
       }
     },
     "@prettier/plugin-xml": {
-      "version": "3.3.1",
-      "resolved": "https://registry.npmjs.org/@prettier/plugin-xml/-/plugin-xml-3.3.1.tgz",
-      "integrity": "sha512-kllNJk6n2pXJjGWdj+HAr1GhOoOTrlmeWkDYCGBzkyZS2l0K6h2gsUQcVif2cNqAE1MNC+nUrzN6QwEsCukPnQ==",
+      "version": "3.4.1",
+      "resolved": "https://registry.npmjs.org/@prettier/plugin-xml/-/plugin-xml-3.4.1.tgz",
+      "integrity": "sha512-Uf/6/+9ez6z/IvZErgobZ2G9n1ybxF5BhCd7eMcKqfoWuOzzNUxBipNo3QAP8kRC1VD18TIo84no7LhqtyDcTg==",
       "dev": true,
       "requires": {
         "@xml-tools/parser": "^1.0.11"
diff --git a/package.json b/package.json
index 57c84826..60dae2da 100644
--- a/package.json
+++ b/package.json
@@ -45,7 +45,7 @@
     }
   },
   "devDependencies": {
-    "@prettier/plugin-xml": "3.3.1",
+    "@prettier/plugin-xml": "3.4.1",
     "husky": "^9.0.11",
     "lint-staged": "15.2.2",
     "prettier": "3.2.5",
diff --git a/release-notes/index.dita b/release-notes/index.dita
index b4f1491a..562389f1 100644
--- a/release-notes/index.dita
+++ b/release-notes/index.dita
@@ -26,14 +26,34 @@
     </refbody>
   </reference>
 
-  <reference id="v4.2.2" outputclass="mark">
+  <reference id="v4.2.3" outputclass="mark">
     <title>DITA-OT <keyword keyref="maintenance-version"/>
-      <!--<ph outputclass="small text-muted">released mmmm D, yyyy</ph>-->
+      <ph outputclass="small text-muted">released May 5, 2024</ph>
     </title>
     <refbody>
       <section id="bugs">
         <p>DITA Open Toolkit <keyword keyref="maintenance-version"/> is a maintenance release that includes the
           following bug fixes.</p>
+        <!-- https://github.com/dita-ot/dita-ot/issues?q=milestone%3A4.2.3+is%3Aclosed+label%3Abug+sort%3Acreated-asc -->
+        <ul>
+          <li id="4449">DITA-OT 4.2.2 included a regression bug that caused the map-first pre-processing routine to fail
+            with a NullPointerException when maps referred to topics that didn’t exist and other topics contained key
+            references. Processing now proceeds and warns of missing files as in previous versions.
+            <xref href="https://github.com/dita-ot/dita-ot/issues/4449" format="html" scope="external">#4449</xref>,
+            <xref href="https://github.com/dita-ot/dita-ot/issues/4454" format="html" scope="external">#4454</xref>
+          </li>
+        </ul>
+      </section>
+    </refbody>
+  </reference>
+  
+  <reference id="v4.2.2">
+    <title>DITA-OT 4.2.2
+      <ph outputclass="small text-muted">released March 24, 2024</ph>
+    </title>
+    <refbody>
+      <section id="bugs">
+        <p>DITA Open Toolkit 4.2.2 is a maintenance release that includes the following bug fixes.</p>
         <!-- https://github.com/dita-ot/dita-ot/issues?q=milestone%3A4.2.2+is%3Aclosed+label%3Abug+sort%3Acreated-asc -->
         <ul>
           <li id="4380">In earlier versions, the map-first pre-processing routine created extra HTML files in the output
diff --git a/resources/key-definitions.ditamap b/resources/key-definitions.ditamap
index 335785c1..aaa7736e 100644
--- a/resources/key-definitions.ditamap
+++ b/resources/key-definitions.ditamap
@@ -26,7 +26,7 @@
   <keydef keys="maintenance-version">
     <topicmeta>
       <keywords>
-        <keyword>4.2.2</keyword>
+        <keyword>4.2.3</keyword>
       </keywords>
     </topicmeta>
   </keydef>
diff --git a/samples/docker/Dockerfile b/samples/docker/Dockerfile
index 3dcc1c77..ae54da57 100644
--- a/samples/docker/Dockerfile
+++ b/samples/docker/Dockerfile
@@ -1,5 +1,5 @@
 # Use the latest DITA-OT image ↓ as parent:
-FROM ghcr.io/dita-ot/dita-ot:4.2.2
+FROM ghcr.io/dita-ot/dita-ot:4.2.3
 
 # Install a custom plug-in from a remote location:
 RUN dita --install https://github.com/infotexture/dita-bootstrap/archive/master.zip