diff --git a/pom.xml b/pom.xml
index 634fe56..ed6b13d 100644
--- a/pom.xml
+++ b/pom.xml
@@ -34,7 +34,7 @@
         <dependency>
             <groupId>org.apache.tomcat</groupId>
             <artifactId>tomcat-dbcp</artifactId>
-            <version>8.5.16</version>
+            <version>8.5.21</version>
             <exclusions>
                 <exclusion>
                     <groupId>org.apache.tomcat</groupId>
@@ -45,12 +45,12 @@
         <dependency>
             <groupId>org.apache.tomcat.embed</groupId>
             <artifactId>tomcat-embed-el</artifactId>
-            <version>8.5.16</version>
+            <version>8.5.21</version>
         </dependency>
         <dependency>
             <groupId>org.apache.tomcat.embed</groupId>
             <artifactId>tomcat-embed-jasper</artifactId>
-            <version>8.5.16</version>
+            <version>8.5.21</version>
             <exclusions>
                 <exclusion>
                     <groupId>org.eclipse.jdt</groupId>
@@ -61,7 +61,7 @@
         <dependency>
             <groupId>org.apache.tomcat.embed</groupId>
             <artifactId>tomcat-embed-websocket</artifactId>
-            <version>8.5.16</version>
+            <version>8.5.21</version>
         </dependency>
     </dependencies>
     <name>Embedded Apache Tomcat 8.5.x</name>