diff --git a/monitor/pom.xml b/monitor/pom.xml
index 220e616..f9b9db3 100644
--- a/monitor/pom.xml
+++ b/monitor/pom.xml
@@ -73,7 +73,7 @@
         <dependency>
             <groupId>org.apache.tomcat</groupId>
             <artifactId>tomcat-catalina</artifactId>
-            <version>11.0.15</version>
+            <version>11.0.21</version>
             <scope>test</scope>
         </dependency>
         <dependency>