diff --git a/geowebcache/pom.xml b/geowebcache/pom.xml
index 1e0a6b51a..8fac3564a 100644
--- a/geowebcache/pom.xml
+++ b/geowebcache/pom.xml
@@ -56,7 +56,7 @@
     <jaiext.version>1.1.27</jaiext.version>
     <spring.version>5.3.39</spring.version>
     <spring.security.version>5.7.13</spring.security.version>
-    <xstream.version>1.4.20</xstream.version>
+    <xstream.version>1.4.21</xstream.version>
     <commons-io.version>2.16.1</commons-io.version>
     <commons-dbcp.version>1.4</commons-dbcp.version>
     <commons-collections.version>4.4</commons-collections.version>