diff --git a/WebGoat/pom.xml b/WebGoat/pom.xml
index 210daa8..d5f7509 100644
--- a/WebGoat/pom.xml
+++ b/WebGoat/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>