diff --git a/pom.xml b/pom.xml
index 5f95d4b2..b6495d57 100644
--- a/pom.xml
+++ b/pom.xml
@@ -149,7 +149,7 @@
     <webwolf.context>/</webwolf.context>
     <wiremock.version>3.9.1</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>