diff --git a/pom.xml b/pom.xml
index 210daa8d64..7d6945a764 100644
--- a/pom.xml
+++ b/pom.xml
@@ -105,7 +105,7 @@
     <webwolf.port>9090</webwolf.port>
     <wiremock.version>3.13.1</wiremock.version>
     <xml-resolver.version>1.2</xml-resolver.version>
-    <xstream.version>1.4.5</xstream.version>
+    <xstream.version>1.4.21</xstream.version>
     <!-- do not update necessary for lesson -->
     <zxcvbn.version>1.9.0</zxcvbn.version>
   </properties>
@@ -553,8 +553,8 @@
               <includes>
                 <include>.gitignore</include>
               </includes>
-              <trimTrailingWhitespace></trimTrailingWhitespace>
-              <endWithNewline></endWithNewline>
+              <trimTrailingWhitespace/>
+              <endWithNewline/>
               <indent>
                 <tabs>true</tabs>
                 <spacesPerTab>4</spacesPerTab>
@@ -565,7 +565,7 @@
             <includes>
               <include>**/*.md</include>
             </includes>
-            <flexmark></flexmark>
+            <flexmark/>
           </markdown>
           <java>
             <includes>
@@ -573,7 +573,7 @@
               <include>src/test/java/**/*.java</include>
               <include>src/it/java/**/*.java</include>
             </includes>
-            <removeUnusedImports></removeUnusedImports>
+            <removeUnusedImports/>
             <googleJavaFormat>
               <style>GOOGLE</style>
               <reflowLongStrings>true</reflowLongStrings>