diff --git a/composer.lock b/composer.lock
index 989ad0eef56aaa89f357f2756392f5083b43f344..25a9dece889aaa6f94e08417fb6c16e87a91820e 100644
--- a/composer.lock
+++ b/composer.lock
@@ -492,7 +492,7 @@
         },
         {
             "name": "drupal/core",
-            "version": "10.4.1",
+            "version": "10.4.x-dev",
             "dist": {
                 "type": "path",
                 "url": "core",
@@ -653,7 +653,7 @@
         },
         {
             "name": "drupal/core-project-message",
-            "version": "10.4.1",
+            "version": "10.4.x-dev",
             "dist": {
                 "type": "path",
                 "url": "composer/Plugin/ProjectMessage",
@@ -686,7 +686,7 @@
         },
         {
             "name": "drupal/core-vendor-hardening",
-            "version": "10.4.1",
+            "version": "10.4.x-dev",
             "dist": {
                 "type": "path",
                 "url": "composer/Plugin/VendorHardening",
@@ -9992,11 +9992,15 @@
     ],
     "aliases": [],
     "minimum-stability": "dev",
-    "stability-flags": {},
+    "stability-flags": {
+        "drupal/core": 20,
+        "drupal/core-project-message": 20,
+        "drupal/core-vendor-hardening": 20
+    },
     "prefer-stable": true,
     "prefer-lowest": false,
-    "platform": {},
-    "platform-dev": {},
+    "platform": [],
+    "platform-dev": [],
     "platform-overrides": {
         "php": "8.1.0"
     },
diff --git a/composer/Metapackage/CoreRecommended/composer.json b/composer/Metapackage/CoreRecommended/composer.json
index 493131f1b3177110c81631d9c8b2ce37e2f05477..11dfa0ebf7f54e20a415233dbe3b27603d8eaba7 100644
--- a/composer/Metapackage/CoreRecommended/composer.json
+++ b/composer/Metapackage/CoreRecommended/composer.json
@@ -7,7 +7,7 @@
         "webflo/drupal-core-strict": "*"
     },
     "require": {
-        "drupal/core": "10.4.1",
+        "drupal/core": "10.4.x-dev",
         "asm89/stack-cors": "~v2.2.0",
         "composer/semver": "~3.4.3",
         "doctrine/annotations": "~1.14.4",
diff --git a/composer/Metapackage/PinnedDevDependencies/composer.json b/composer/Metapackage/PinnedDevDependencies/composer.json
index 5ebeefdac94818e36363f29c68a6a7487311a7c8..98564cebc4a064f569061cd3ce370445be833d98 100644
--- a/composer/Metapackage/PinnedDevDependencies/composer.json
+++ b/composer/Metapackage/PinnedDevDependencies/composer.json
@@ -7,7 +7,7 @@
         "webflo/drupal-core-require-dev": "*"
     },
     "require": {
-        "drupal/core": "10.4.1",
+        "drupal/core": "10.4.x-dev",
         "behat/mink": "v1.12.0",
         "behat/mink-browserkit-driver": "v2.2.0",
         "brick/math": "0.12.1",
diff --git a/composer/Template/LegacyProject/composer.json b/composer/Template/LegacyProject/composer.json
index 0921a0d2da816e53babd171bb3d6426931e09da7..508b5b36460ba34dc36052a0db6517a0c16e2ad8 100644
--- a/composer/Template/LegacyProject/composer.json
+++ b/composer/Template/LegacyProject/composer.json
@@ -27,7 +27,7 @@
     "conflict": {
         "drupal/drupal": "*"
     },
-    "minimum-stability": "stable",
+    "minimum-stability": "dev",
     "prefer-stable": true,
     "config": {
         "allow-plugins": {
diff --git a/composer/Template/RecommendedProject/composer.json b/composer/Template/RecommendedProject/composer.json
index b91df479dd178a5e11c864f071f544d9e8f07aae..032ef9ff94b84c875c0008716ad8084ef11de994 100644
--- a/composer/Template/RecommendedProject/composer.json
+++ b/composer/Template/RecommendedProject/composer.json
@@ -26,7 +26,7 @@
     "conflict": {
         "drupal/drupal": "*"
     },
-    "minimum-stability": "stable",
+    "minimum-stability": "dev",
     "prefer-stable": true,
     "config": {
         "allow-plugins": {
diff --git a/core/lib/Drupal.php b/core/lib/Drupal.php
index 81cfe7a1351cf13daceddf3b2fbd4cc032fce2f5..fc8016d0d7603ae18e9df84c299ee5beb24561f3 100644
--- a/core/lib/Drupal.php
+++ b/core/lib/Drupal.php
@@ -75,7 +75,7 @@ class Drupal {
   /**
    * The current system version.
    */
-  const VERSION = '10.4.1';
+  const VERSION = '10.4.2-dev';
 
   /**
    * Core API compatibility.
diff --git a/core/lib/Drupal/Component/Annotation/composer.json b/core/lib/Drupal/Component/Annotation/composer.json
index a8769629a58bd3cdfe2801b86d6f5df93fca9f2e..697c06f01097c40a0a171db297e6977a33edca55 100644
--- a/core/lib/Drupal/Component/Annotation/composer.json
+++ b/core/lib/Drupal/Component/Annotation/composer.json
@@ -9,10 +9,10 @@
     "require": {
         "php": ">=8.1.0",
         "doctrine/annotations": "^1.14",
-        "drupal/core-class-finder": "^10.4",
-        "drupal/core-file-cache": "^10.4",
-        "drupal/core-plugin": "^10.4",
-        "drupal/core-utility": "^10.4"
+        "drupal/core-class-finder": "10.4.x-dev",
+        "drupal/core-file-cache": "10.4.x-dev",
+        "drupal/core-plugin": "10.4.x-dev",
+        "drupal/core-utility": "10.4.x-dev"
     },
     "autoload": {
         "psr-4": {
diff --git a/core/lib/Drupal/Component/Datetime/composer.json b/core/lib/Drupal/Component/Datetime/composer.json
index f4d8b7125afba8bff2209cf9f6f1688593d0f999..e35cc2cda1a2e2552d3c352f3b00b223ec9badba 100644
--- a/core/lib/Drupal/Component/Datetime/composer.json
+++ b/core/lib/Drupal/Component/Datetime/composer.json
@@ -8,7 +8,7 @@
     "license": "GPL-2.0-or-later",
     "require": {
         "php": ">=8.1.0",
-        "drupal/core-utility": "^10.4"
+        "drupal/core-utility": "10.4.x-dev"
     },
     "autoload": {
         "psr-4": {
diff --git a/core/lib/Drupal/Component/Discovery/composer.json b/core/lib/Drupal/Component/Discovery/composer.json
index b241b980dc10a3251de2d6d775219ca0bc4467f5..34d34067c175fc7c4888faad7679cb3d5eb02faa 100644
--- a/core/lib/Drupal/Component/Discovery/composer.json
+++ b/core/lib/Drupal/Component/Discovery/composer.json
@@ -8,8 +8,8 @@
     "license": "GPL-2.0-or-later",
     "require": {
         "php": ">=8.1.0",
-        "drupal/core-file-cache": "^10.4",
-        "drupal/core-serialization": "^10.4"
+        "drupal/core-file-cache": "10.4.x-dev",
+        "drupal/core-serialization": "10.4.x-dev"
     },
     "autoload": {
         "psr-4": {
diff --git a/core/lib/Drupal/Component/FrontMatter/composer.json b/core/lib/Drupal/Component/FrontMatter/composer.json
index 63d75e93ffcc9fc91cb4fd09e2d4ce0afb6893e0..3ac47f3785b2550220f299a67ccdda5fe80cf914 100644
--- a/core/lib/Drupal/Component/FrontMatter/composer.json
+++ b/core/lib/Drupal/Component/FrontMatter/composer.json
@@ -8,7 +8,7 @@
     "license": "GPL-2.0-or-later",
     "require": {
         "php": ">=8.1.0",
-        "drupal/core-serialization": "^10.4"
+        "drupal/core-serialization": "10.4.x-dev"
     },
     "autoload": {
         "psr-4": {
diff --git a/core/lib/Drupal/Component/Gettext/composer.json b/core/lib/Drupal/Component/Gettext/composer.json
index 56c5d1d08cc43cffabdf932668cde314f30de7f3..6b731b3c158a084cc2f05431fc7bc1e597b28b16 100644
--- a/core/lib/Drupal/Component/Gettext/composer.json
+++ b/core/lib/Drupal/Component/Gettext/composer.json
@@ -9,7 +9,7 @@
     },
     "require": {
         "php": ">=8.1.0",
-        "drupal/core-render": "^10.4"
+        "drupal/core-render": "10.4.x-dev"
     },
     "autoload": {
         "psr-4": {
diff --git a/core/lib/Drupal/Component/PhpStorage/composer.json b/core/lib/Drupal/Component/PhpStorage/composer.json
index 73c49b7a5952e5053bb130a70a422316b4bb82f9..395e10d24350ab7a90fbe16855eda7de99e23b4d 100644
--- a/core/lib/Drupal/Component/PhpStorage/composer.json
+++ b/core/lib/Drupal/Component/PhpStorage/composer.json
@@ -8,7 +8,7 @@
     "license": "GPL-2.0-or-later",
     "require": {
         "php": ">=8.1.0",
-        "drupal/core-file-security": "^10.4"
+        "drupal/core-file-security": "10.4.x-dev"
     },
     "autoload": {
         "psr-4": {
diff --git a/core/lib/Drupal/Component/Render/composer.json b/core/lib/Drupal/Component/Render/composer.json
index df2bcf5f4ccea2dc300595ca34e253d477db1c62..72c0060d2669a2774b2e205768352a88bbe17ed3 100644
--- a/core/lib/Drupal/Component/Render/composer.json
+++ b/core/lib/Drupal/Component/Render/composer.json
@@ -8,7 +8,7 @@
     "license": "GPL-2.0-or-later",
     "require": {
         "php": ">=8.1.0",
-        "drupal/core-utility": "^10.4"
+        "drupal/core-utility": "10.4.x-dev"
     },
     "autoload": {
         "psr-4": {