diff --git a/access-control/pom.xml b/access-control/pom.xml
index 40bfb57..804bfff 100644
--- a/access-control/pom.xml
+++ b/access-control/pom.xml
@@ -41,7 +41,7 @@
     <dependency>
       <groupId>com.thoughtworks.xstream</groupId>
       <artifactId>xstream</artifactId>
-      <version>1.4.6</version>
+      <version>1.4.18</version>
     </dependency>
     <dependency>
       <groupId>org.codehaus.jettison</groupId>