diff --git a/.github/workflows/ci-e2e.yaml b/.github/workflows/ci-e2e.yaml
index 394df8e4..06a6b8d3 100644
--- a/.github/workflows/ci-e2e.yaml
+++ b/.github/workflows/ci-e2e.yaml
@@ -20,7 +20,7 @@ jobs:
     name: Integration tests with MySQL
     strategy:
       matrix:
-        mysql-version: ["8.0.28", "8.0.36", "8.0.37", "8.4.0"]
+        mysql-version: ["8.0.28", "8.0.36", "8.0.37", "8.4.0", "8.4.2"]
     runs-on: ubuntu-22.04
     steps:
       - uses: actions/checkout@v4
@@ -40,7 +40,7 @@ jobs:
     name: Supported Kubernetes versions End-to-End Tests
     strategy:
       matrix:
-        mysql-version: ["8.4.0"]
+        mysql-version: ["8.4.2"]
         k8s-version: ["1.27.13", "1.28.9", "1.29.4", "1.30.4"]
     runs-on:
       group: moco
@@ -64,7 +64,7 @@ jobs:
     name: Supported MySQL versions End-to-End Tests
     strategy:
       matrix:
-        mysql-version: ["8.0.28", "8.0.36", "8.0.37", "8.4.0"]
+        mysql-version: ["8.0.28", "8.0.36", "8.0.37", "8.4.0", "8.4.2"]
         k8s-version: ["1.31.0"]
     runs-on:
       group: moco
diff --git a/DEVELOP.md b/DEVELOP.md
index 1cf535f7..911bb4d6 100644
--- a/DEVELOP.md
+++ b/DEVELOP.md
@@ -54,7 +54,7 @@ Edit the following lines in `Dockerfile`:
 
 ```
 # The tag should be the latest one
-FROM ghcr.io/cybozu-go/moco/mysql:8.4.0.1 as mysql
+FROM ghcr.io/cybozu-go/moco/mysql:8.4.2.1 as mysql
 
 # See the below description for how to get the version string.
 ARG MYSQLSH_VERSION=8.4.0-1
@@ -84,14 +84,14 @@ MySQL versions appear twice:
     name: Integration tests with MySQL
     strategy:
       matrix:
-        mysql-version: ["8.0.28", "8.0.36", "8.0.37", "8.4.0"]
+        mysql-version: ["8.0.28", "8.0.36", "8.0.37", "8.4.0", "8.4.2"]
 ...
   # Matrix tests for the latest MySQL version on different Kubernetes versions.
   e2e:
     name: Supported Kubernetes versions End-to-End Tests
     strategy:
       matrix:
-        mysql-version: ["8.4.0"]
+        mysql-version: ["8.4.2"]
         k8s-version: ["1.29.4", "1.30.4", "1.31.0"]
 ...
   # Matrix tests for different MySQL versions on the latest supported Kubernetes version.
@@ -99,7 +99,7 @@ MySQL versions appear twice:
     name: Supported MySQL versions End-to-End Tests
     strategy:
       matrix:
-        mysql-version: ["8.0.28", "8.0.36", "8.0.37", "8.4.0"]
+        mysql-version: ["8.0.28", "8.0.36", "8.0.37", "8.4.0", "8.4.2"]
         k8s-version: ["1.31.0"]
 ```
 
diff --git a/README.md b/README.md
index 9cb0b504..ad2eb520 100644
--- a/README.md
+++ b/README.md
@@ -26,7 +26,7 @@ Blog article: [Introducing MOCO, a modern MySQL operator on Kubernetes](https://
 
 ## Supported software
 
-- MySQL: 8.0.28, 8.0.36, 8.0.37, 8.4.0
+- MySQL: 8.0.28, 8.0.36, 8.0.37, 8.4.0, 8.4.2
 - Kubernetes: 1.29, 1.30,1.31
 
 MOCO supports (tests) the LTS releases of MySQL 8.
diff --git a/docs/change-pvc-template.md b/docs/change-pvc-template.md
index 66bc4be2..f2a9b9dc 100644
--- a/docs/change-pvc-template.md
+++ b/docs/change-pvc-template.md
@@ -93,7 +93,7 @@ For example, the user modifies the `.spec.volumeClaimTemplates` of the MySQLClus
       spec:
         containers:
         - name: mysqld
-          image: ghcr.io/cybozu-go/moco/mysql:8.4.0
+          image: ghcr.io/cybozu-go/moco/mysql:8.4.2
     volumeClaimTemplates:
     - metadata:
         name: mysql-data
diff --git a/docs/custom-mysqld.md b/docs/custom-mysqld.md
index 4e44db6b..0e64d0fc 100644
--- a/docs/custom-mysqld.md
+++ b/docs/custom-mysqld.md
@@ -11,7 +11,7 @@ spec:
     spec:
       containers:
       - name: mysqld
-        image: ghcr.io/cybozu-go/moco/mysql:8.4.0
+        image: ghcr.io/cybozu-go/moco/mysql:8.4.2
 ```
 
 If you want to build and use your own `mysqld`, read the rest of this document.
@@ -35,9 +35,9 @@ On Ubuntu 22.04, you can build the source code as follows:
 $ sudo apt-get update
 $ sudo apt-get -y --no-install-recommends install build-essential libssl-dev \
     cmake libncurses5-dev libjemalloc-dev libnuma-dev libaio-dev pkg-config
-$ curl -fsSL -O https://dev.mysql.com/get/Downloads/MySQL-8.4/mysql-8.4.0.tar.gz
-$ tar -x -z -f mysql-8.4.0.tar.gz
-$ cd mysql-8.4.0
+$ curl -fsSL -O https://dev.mysql.com/get/Downloads/MySQL-8.4/mysql-8.4.2.tar.gz
+$ tar -x -z -f mysql-8.4.2.tar.gz
+$ cd mysql-8.4.2
 $ mkdir bld
 $ cd bld
 $ cmake .. -DBUILD_CONFIG=mysql_release -DCMAKE_BUILD_TYPE=Release \
diff --git a/docs/designdoc/allow_customize_containers.md b/docs/designdoc/allow_customize_containers.md
index 6a1b2f43..e061a474 100644
--- a/docs/designdoc/allow_customize_containers.md
+++ b/docs/designdoc/allow_customize_containers.md
@@ -32,7 +32,7 @@ spec:
     spec:
       containers:
       - name: mysqld
-        image: ghcr.io/cybozu-go/moco/mysql:8.4.0
+        image: ghcr.io/cybozu-go/moco/mysql:8.4.2
     overwriteContainers:
     - name: agent
       resources:
@@ -95,7 +95,7 @@ spec:
     spec:
       containers:
       - name: mysqld
-        image: ghcr.io/cybozu-go/moco/mysql:8.4.0
+        image: ghcr.io/cybozu-go/moco/mysql:8.4.2
     overwriteContainers:
       agent:
         resources:
diff --git a/docs/designdoc/support_reduce_volume_size.md b/docs/designdoc/support_reduce_volume_size.md
index 69bac515..41c21fe3 100644
--- a/docs/designdoc/support_reduce_volume_size.md
+++ b/docs/designdoc/support_reduce_volume_size.md
@@ -45,7 +45,7 @@ For example, the user modifies the `.spec.volumeClaimTemplates` of the MySQLClus
       spec:
         containers:
         - name: mysqld
-          image: ghcr.io/cybozu-go/moco/mysql:8.4.0
+          image: ghcr.io/cybozu-go/moco/mysql:8.4.2
     volumeClaimTemplates:
     - metadata:
         name: mysql-data
diff --git a/docs/usage.md b/docs/usage.md
index 264ab7f7..fc927032 100644
--- a/docs/usage.md
+++ b/docs/usage.md
@@ -101,7 +101,7 @@ spec:
       containers:
       # At least a container named "mysqld" must be defined.
       - name: mysqld
-        image: ghcr.io/cybozu-go/moco/mysql:8.4.0
+        image: ghcr.io/cybozu-go/moco/mysql:8.4.2
         # By limiting CPU and memory, Pods will have Guaranteed QoS class.
         # requests can be omitted; it will be set to the same value as limits.
         resources:
@@ -209,7 +209,7 @@ spec:
     spec:
       containers:
       - name: mysqld
-        image: ghcr.io/cybozu-go/moco/mysql:8.4.0  # must be the same version as the donor
+        image: ghcr.io/cybozu-go/moco/mysql:8.4.2  # must be the same version as the donor
   volumeClaimTemplates:
   - metadata:
       name: mysql-data
@@ -728,7 +728,7 @@ spec:
       containers:
       - name: mysqld
         # Edit the next line
-        image: ghcr.io/cybozu-go/moco/mysql:8.4.0
+        image: ghcr.io/cybozu-go/moco/mysql:8.4.2
 ```
 
 You are advised to make backups and/or create a replica cluster before starting the upgrade process.
diff --git a/e2e/Makefile b/e2e/Makefile
index b4e9b6a3..75786a1e 100644
--- a/e2e/Makefile
+++ b/e2e/Makefile
@@ -1,7 +1,7 @@
 KIND_VERSION = 0.23.0
 KUBERNETES_VERSION = 1.31.0
 CERT_MANAGER_VERSION = 1.15.2
-MYSQL_VERSION = 8.4.0
+MYSQL_VERSION = 8.4.2
 
 KIND := $(dir $(shell pwd))/bin/kind
 KUBECTL := $(dir $(shell pwd))/bin/kubectl
diff --git a/e2e/upgrade_test.go b/e2e/upgrade_test.go
index 3125157e..b8312454 100644
--- a/e2e/upgrade_test.go
+++ b/e2e/upgrade_test.go
@@ -20,7 +20,7 @@ var upgradeYAML string
 
 const (
 	mysqlVersionOld = "8.0.28"
-	mysqlVersionNew = "8.4.0"
+	mysqlVersionNew = "8.4.2"
 )
 
 var _ = Context("upgrade", func() {
diff --git a/examples/anti-affinity.yaml b/examples/anti-affinity.yaml
index 5410d5ab..36d6dfb4 100644
--- a/examples/anti-affinity.yaml
+++ b/examples/anti-affinity.yaml
@@ -26,7 +26,7 @@ spec:
             topologyKey: "kubernetes.io/hostname"
       containers:
       - name: mysqld
-        image: ghcr.io/cybozu-go/moco/mysql:8.4.0
+        image: ghcr.io/cybozu-go/moco/mysql:8.4.2
         resources:
           requests:
             cpu: "10"
diff --git a/examples/collect-metrics.yaml b/examples/collect-metrics.yaml
index 1fa90aff..2b5a7857 100644
--- a/examples/collect-metrics.yaml
+++ b/examples/collect-metrics.yaml
@@ -14,7 +14,7 @@ spec:
     spec:
       containers:
       - name: mysqld
-        image: ghcr.io/cybozu-go/moco/mysql:8.4.0
+        image: ghcr.io/cybozu-go/moco/mysql:8.4.2
   volumeClaimTemplates:
   - metadata:
       name: mysql-data
diff --git a/examples/custom-mycnf.yaml b/examples/custom-mycnf.yaml
index 3c808d50..bfa69b8a 100644
--- a/examples/custom-mycnf.yaml
+++ b/examples/custom-mycnf.yaml
@@ -24,7 +24,7 @@ spec:
     spec:
       containers:
       - name: mysqld
-        image: ghcr.io/cybozu-go/moco/mysql:8.4.0
+        image: ghcr.io/cybozu-go/moco/mysql:8.4.2
   volumeClaimTemplates:
   - metadata:
       name: mysql-data
diff --git a/examples/custom-probe.yaml b/examples/custom-probe.yaml
index 70343e3e..c67f0721 100644
--- a/examples/custom-probe.yaml
+++ b/examples/custom-probe.yaml
@@ -10,7 +10,7 @@ spec:
     spec:
       containers:
         - name: mysqld
-          image: ghcr.io/cybozu-go/moco/mysql:8.4.0
+          image: ghcr.io/cybozu-go/moco/mysql:8.4.2
           # If you want to override the default probes, you cannot override the httpGet.
           livenessProbe:
             failureThreshold: 3
diff --git a/examples/guaranteed.yaml b/examples/guaranteed.yaml
index 38901249..d1731ef7 100644
--- a/examples/guaranteed.yaml
+++ b/examples/guaranteed.yaml
@@ -10,7 +10,7 @@ spec:
     spec:
       containers:
       - name: mysqld
-        image: ghcr.io/cybozu-go/moco/mysql:8.4.0
+        image: ghcr.io/cybozu-go/moco/mysql:8.4.2
         # By limiting CPU and memory, Pods will have Guaranteed QoS class.
         # requests can be omitted; it will be set to the same value as limits.
         resources:
diff --git a/examples/loadbalancer.yaml b/examples/loadbalancer.yaml
index e0353dab..1e73ae1f 100644
--- a/examples/loadbalancer.yaml
+++ b/examples/loadbalancer.yaml
@@ -18,7 +18,7 @@ spec:
     spec:
       containers:
       - name: mysqld
-        image: ghcr.io/cybozu-go/moco/mysql:8.4.0
+        image: ghcr.io/cybozu-go/moco/mysql:8.4.2
   volumeClaimTemplates:
   - metadata:
       name: mysql-data