diff --git a/build.gradle.kts b/build.gradle.kts
index 2cbec239..b0ae7623 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -52,7 +52,7 @@ subprojects {
         set("spotBugsVersion", "4.8.0")         // https://mvnrepository.com/artifact/com.github.spotbugs/spotbugs-annotations
         set("jacksonVersion", "2.15.3")         // https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-annotations
         set("slf4jVersion", "2.0.9")            // https://mvnrepository.com/artifact/org.slf4j/slf4j-api
-        set("log4jVersion", "2.20.0")           // https://mvnrepository.com/artifact/org.apache.logging.log4j/log4j-core
+        set("log4jVersion", "2.21.1")           // https://mvnrepository.com/artifact/org.apache.logging.log4j/log4j-core
         set("guavaVersion", "32.1.2-jre")         // https://mvnrepository.com/artifact/com.google.guava/guava
         set("junitVersion", "5.10.0")            // https://mvnrepository.com/artifact/org.junit.jupiter/junit-jupiter-api
         set("junitPioneerVersion", "2.1.0")     // https://mvnrepository.com/artifact/org.junit-pioneer/junit-pioneer