diff --git a/.github/workflows/notifications-test-and-build-workflow.yml b/.github/workflows/notifications-test-and-build-workflow.yml
index 4f758317..58440396 100644
--- a/.github/workflows/notifications-test-and-build-workflow.yml
+++ b/.github/workflows/notifications-test-and-build-workflow.yml
@@ -19,7 +19,7 @@ jobs:
       # This setting says that all jobs should finish, even if one fails
       fail-fast: false
       matrix:
-        java: [11, 17]
+        java: [11, 17, 21]
 
     # Job name
     name: Build Notifications with JDK ${{ matrix.java }} on linux
@@ -82,7 +82,7 @@ jobs:
       # This setting says that all jobs should finish, even if one fails
       fail-fast: false
       matrix:
-        java: [11, 17]
+        java: [11, 17, 21]
         os: [ windows-latest, macos-latest ]
         include:
           - os: windows-latest
diff --git a/.github/workflows/security-notifications-test-workflow.yml b/.github/workflows/security-notifications-test-workflow.yml
index 31352b76..8689df12 100644
--- a/.github/workflows/security-notifications-test-workflow.yml
+++ b/.github/workflows/security-notifications-test-workflow.yml
@@ -13,7 +13,7 @@ jobs:
       # This setting says that all jobs should finish, even if one fails
       fail-fast: false
       matrix:
-        java: [11, 17]
+        java: [11, 17, 21]
 
     runs-on: ubuntu-latest
 
diff --git a/notifications/build-tools/merged-coverage.gradle b/notifications/build-tools/merged-coverage.gradle
index 03a3b6fc..601a3ff6 100644
--- a/notifications/build-tools/merged-coverage.gradle
+++ b/notifications/build-tools/merged-coverage.gradle
@@ -5,7 +5,7 @@
 
 allprojects {
     plugins.withId('jacoco') {
-        jacoco.toolVersion = '0.8.7'
+        jacoco.toolVersion = '0.8.11'
         // For some reason this dependency isn't getting setup automatically by the jacoco plugin
         tasks.withType(JacocoReport) { 
             dependsOn tasks.withType(Test)
diff --git a/notifications/build.gradle b/notifications/build.gradle
index 899d50d4..65328466 100644
--- a/notifications/build.gradle
+++ b/notifications/build.gradle
@@ -39,7 +39,7 @@ buildscript {
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:${kotlin_version}"
         classpath "org.jetbrains.kotlin:kotlin-allopen:${kotlin_version}"
         classpath "io.gitlab.arturbosch.detekt:detekt-gradle-plugin:1.23.0"
-        classpath "org.jacoco:org.jacoco.agent:0.8.7"
+        classpath "org.jacoco:org.jacoco.agent:0.8.11"
     }
 }
 
diff --git a/notifications/core/build.gradle b/notifications/core/build.gradle
index f64402cf..58288864 100644
--- a/notifications/core/build.gradle
+++ b/notifications/core/build.gradle
@@ -9,7 +9,7 @@ plugins {
     id 'jacoco'
     id 'maven-publish'
     id 'signing'
-    id "com.netflix.nebula.ospackage" version "11.3.0"
+    id "com.netflix.nebula.ospackage" version "11.5.0"
 }
 
 repositories {
@@ -149,7 +149,7 @@ dependencies {
             'org.assertj:assertj-core:3.16.1',
             'org.junit.jupiter:junit-jupiter-api:5.6.2',
             "org.junit.jupiter:junit-jupiter-params:5.6.2",
-            "org.easymock:easymock:4.0.1",
+            "org.easymock:easymock:5.2.0",
             "org.apache.logging.log4j:log4j-core:${versions.log4j}",
             'org.mockito:mockito-junit-jupiter:3.10.0',
             'com.nhaarman.mockitokotlin2:mockito-kotlin:2.2.0',
diff --git a/notifications/gradle/wrapper/gradle-wrapper.jar b/notifications/gradle/wrapper/gradle-wrapper.jar
index c1962a79..d64cd491 100644
Binary files a/notifications/gradle/wrapper/gradle-wrapper.jar and b/notifications/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/notifications/gradle/wrapper/gradle-wrapper.properties b/notifications/gradle/wrapper/gradle-wrapper.properties
index 37aef8d3..ca8f2653 100644
--- a/notifications/gradle/wrapper/gradle-wrapper.properties
+++ b/notifications/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,7 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.1.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.5-bin.zip
 networkTimeout=10000
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
+distributionSha256Sum=9d926787066a081739e8200858338b4a69e837c3a821a33aca9db09dd4a41026
diff --git a/notifications/gradlew b/notifications/gradlew
index aeb74cbb..1aa94a42 100755
--- a/notifications/gradlew
+++ b/notifications/gradlew
@@ -83,7 +83,8 @@ done
 # This is normally unused
 # shellcheck disable=SC2034
 APP_BASE_NAME=${0##*/}
-APP_HOME=$( cd "${APP_HOME:-./}" && pwd -P ) || exit
+# Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036)
+APP_HOME=$( cd "${APP_HOME:-./}" > /dev/null && pwd -P ) || exit
 
 # Use the maximum available, or set MAX_FD != -1 to use that value.
 MAX_FD=maximum
@@ -130,10 +131,13 @@ location of your Java installation."
     fi
 else
     JAVACMD=java
-    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+    if ! command -v java >/dev/null 2>&1
+    then
+        die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
 
 Please set the JAVA_HOME variable in your environment to match the
 location of your Java installation."
+    fi
 fi
 
 # Increase the maximum file descriptors if we can.
@@ -141,7 +145,7 @@ if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
     case $MAX_FD in #(
       max*)
         # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked.
-        # shellcheck disable=SC3045
+        # shellcheck disable=SC2039,SC3045
         MAX_FD=$( ulimit -H -n ) ||
             warn "Could not query maximum file descriptor limit"
     esac
@@ -149,7 +153,7 @@ if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
       '' | soft) :;; #(
       *)
         # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
-        # shellcheck disable=SC3045
+        # shellcheck disable=SC2039,SC3045
         ulimit -n "$MAX_FD" ||
             warn "Could not set maximum file descriptor limit to $MAX_FD"
     esac
@@ -198,11 +202,11 @@ fi
 # Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
 DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
 
-# Collect all arguments for the java command;
-#   * $DEFAULT_JVM_OPTS, $JAVA_OPTS, and $GRADLE_OPTS can contain fragments of
-#     shell script including quotes and variable substitutions, so put them in
-#     double quotes to make sure that they get re-expanded; and
-#   * put everything else in single quotes, so that it's not re-expanded.
+# Collect all arguments for the java command:
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments,
+#     and any embedded shellness will be escaped.
+#   * For example: A user cannot expect ${Hostname} to be expanded, as it is an environment variable and will be
+#     treated as '${Hostname}' itself on the command line.
 
 set -- \
         "-Dorg.gradle.appname=$APP_BASE_NAME" \
diff --git a/notifications/notifications/build.gradle b/notifications/notifications/build.gradle
index 14f686ce..7d45e886 100644
--- a/notifications/notifications/build.gradle
+++ b/notifications/notifications/build.gradle
@@ -10,7 +10,7 @@ import java.util.concurrent.Callable
 
 plugins {
     id "com.dorongold.task-tree" version "2.1.1"
-    id "com.netflix.nebula.ospackage" version "11.3.0"
+    id "com.netflix.nebula.ospackage" version "11.5.0"
 }
 
 apply plugin: 'java'