diff --git a/build.gradle b/build.gradle
index d2c95b0104..d21802d8d3 100644
--- a/build.gradle
+++ b/build.gradle
@@ -124,7 +124,7 @@ subprojects {
         commonsIoVersion = '2.14.0'
         commonsMathVersion = '3.6.1'
         junitVersion = '5.10.0'
-        log4jVersion = '2.20.0'
+        log4jVersion = '2.21.0'
         mockitoVersion = '4.11.0'
         hamcrestVersion = '2.2'
         xmlbeansVersion = '5.1.1'
diff --git a/build.xml b/build.xml
index 385bc73988..f81c89d0f6 100644
--- a/build.xml
+++ b/build.xml
@@ -268,7 +268,7 @@ under the License.
     <dependency prefix="main.commons-math3" artifact="org.apache.commons:commons-math3:3.6.1" usage="main"/>
     <dependency prefix="main.commons-io" artifact="commons-io:commons-io:2.14.0" usage="main"/>
     <dependency prefix="main.com.zaxxer" artifact="com.zaxxer:SparseBitSet:1.3" usage="main"/>
-    <dependency prefix="main.log4j-api" artifact="org.apache.logging.log4j:log4j-api:2.20.0" usage="main"/>
+    <dependency prefix="main.log4j-api" artifact="org.apache.logging.log4j:log4j-api:2.21.0" usage="main"/>
 
     <dependency prefix="main.junit-api" artifact="org.junit.jupiter:junit-jupiter-api:5.10.0" usage="main-tests"/>
     <dependency prefix="main.junit-jengine" artifact="org.junit.jupiter:junit-jupiter-engine:5.10.0" usage="main-tests"/>
@@ -288,7 +288,7 @@ under the License.
     <dependency prefix="main.byte-buddy" artifact="net.bytebuddy:byte-buddy:1.14.7" usage="main-tests"/>
     <dependency prefix="main.byte-buddy-agent" artifact="net.bytebuddy:byte-buddy-agent:1.14.7" usage="main-tests"/>
     <dependency prefix="main.objenesis" artifact="org.objenesis:objenesis:3.1" usage="main-tests"/>
-    <dependency prefix="main.log4j-core" artifact="org.apache.logging.log4j:log4j-core:2.20.0" usage="main-tests"/>
+    <dependency prefix="main.log4j-core" artifact="org.apache.logging.log4j:log4j-core:2.21.0" usage="main-tests"/>
     <dependency prefix="main.commons-logging" artifact="commons-logging:commons-logging:1.2" usage="main-tests"/>
 
     <dependency prefix="main.ant" artifact="org.apache.ant:ant:1.10.14" usage="excelant"/>
diff --git a/osgi/pom.xml b/osgi/pom.xml
index 770fff480b..5b4d69c0dd 100644
--- a/osgi/pom.xml
+++ b/osgi/pom.xml
@@ -231,7 +231,7 @@
         <dependency>
             <groupId>org.apache.logging.log4j</groupId>
             <artifactId>log4j-core</artifactId>
-            <version>2.20.0</version>
+            <version>2.21.0</version>
             <scope>test</scope>
         </dependency>
     </dependencies>