diff --git a/core/src/main/java/org/correomqtt/core/utils/VersionUtils.java b/core/src/main/java/org/correomqtt/core/utils/VersionUtils.java
index bfd461478..02ceee3d4 100644
--- a/core/src/main/java/org/correomqtt/core/utils/VersionUtils.java
+++ b/core/src/main/java/org/correomqtt/core/utils/VersionUtils.java
@@ -26,7 +26,7 @@ public class VersionUtils {
 
     private static String version;
 
-    private static final Pattern MAJOR_MINOR_PATTERN = Pattern.compile("$([0-9]+).([0-9]+)");
+    private static final Pattern MAJOR_MINOR_PATTERN = Pattern.compile("^([0-9]+).([0-9]+)");
 
     private VersionUtils() {
         // private constructor
diff --git a/plugins/xml-format/src/main/java/org/correomqtt/plugin/xml_format/CustomXMLConstants.java b/plugins/xml-format/src/main/java/org/correomqtt/plugin/xml_format/CustomXMLConstants.java
new file mode 100644
index 000000000..2342c8b05
--- /dev/null
+++ b/plugins/xml-format/src/main/java/org/correomqtt/plugin/xml_format/CustomXMLConstants.java
@@ -0,0 +1,10 @@
+package org.correomqtt.plugin.xml_format;
+
+public final class CustomXMLConstants {
+    public static final String NULL_NS_URI = "";
+
+    public static final String FEATURE_DISALLOW_DOCTYPE_DECL = "http://apache.org/xml/features/disallow-doctype-decl";
+    private CustomXMLConstants() {
+    }
+}
+
diff --git a/plugins/xml-format/src/main/java/org/correomqtt/plugin/xml_format/XmlFormatPlugin.java b/plugins/xml-format/src/main/java/org/correomqtt/plugin/xml_format/XmlFormatPlugin.java
index 993c1992e..343f503c9 100644
--- a/plugins/xml-format/src/main/java/org/correomqtt/plugin/xml_format/XmlFormatPlugin.java
+++ b/plugins/xml-format/src/main/java/org/correomqtt/plugin/xml_format/XmlFormatPlugin.java
@@ -143,6 +143,7 @@ private Document getXmlDocument() {
     private Document createXmlDocument() {
         DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
         try {
+            factory.setFeature(CustomXMLConstants.FEATURE_DISALLOW_DOCTYPE_DECL, true);
             factory.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, true);
         } catch (ParserConfigurationException e) {
             LOGGER.debug("Could not configure document builder factory. ", e);
@@ -184,6 +185,7 @@ public String getPrettyString() {
         TransformerFactory transformerFactory = TransformerFactory.newInstance();
         Transformer transformer;
         try {
+            transformerFactory.setFeature(CustomXMLConstants.FEATURE_DISALLOW_DOCTYPE_DECL, true);
             transformerFactory.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, true);
             transformer = transformerFactory.newTransformer();
         } catch (TransformerConfigurationException e) {