diff --git a/core/pom.xml b/core/pom.xml
index 17f0317a3..a34792f4f 100644
--- a/core/pom.xml
+++ b/core/pom.xml
@@ -101,7 +101,7 @@
     <dependency>
       <groupId>com.thoughtworks.xstream</groupId>
       <artifactId>xstream</artifactId>
-      <version>1.4.20</version>
+      <version>1.4.21</version>
       <type>jar</type>
       <scope>compile</scope>
     </dependency>