diff --git a/server/pom.xml b/server/pom.xml
index 3929640..6a75cf7 100644
--- a/server/pom.xml
+++ b/server/pom.xml
@@ -191,7 +191,7 @@
         <dependency>
             <groupId>com.thoughtworks.xstream</groupId>
             <artifactId>xstream</artifactId>
-            <version>1.4.18</version>
+            <version>1.4.20</version>
         </dependency>
         <dependency>
             <groupId>com.googlecode.concurrentlinkedhashmap</groupId>