diff --git a/composer.lock b/composer.lock
index 317b69262b052db751c3f9f8343771f65a8a4f17..9b5dfd849e13f4c341c5e50049245cf642c4713c 100644
--- a/composer.lock
+++ b/composer.lock
@@ -491,7 +491,7 @@
         },
         {
             "name": "drupal/core",
-            "version": "10.3.7",
+            "version": "10.3.x-dev",
             "dist": {
                 "type": "path",
                 "url": "core",
@@ -652,7 +652,7 @@
         },
         {
             "name": "drupal/core-project-message",
-            "version": "10.3.7",
+            "version": "10.3.x-dev",
             "dist": {
                 "type": "path",
                 "url": "composer/Plugin/ProjectMessage",
@@ -685,7 +685,7 @@
         },
         {
             "name": "drupal/core-vendor-hardening",
-            "version": "10.3.7",
+            "version": "10.3.x-dev",
             "dist": {
                 "type": "path",
                 "url": "composer/Plugin/VendorHardening",
@@ -9611,11 +9611,15 @@
     ],
     "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 7ec9311d39245f1fd9a7c1e107f2af4eedc20a7b..5c7d51d74f3edbdd3ff138e8b92c19b26e58b98c 100644
--- a/composer/Metapackage/CoreRecommended/composer.json
+++ b/composer/Metapackage/CoreRecommended/composer.json
@@ -7,7 +7,7 @@
         "webflo/drupal-core-strict": "*"
     },
     "require": {
-        "drupal/core": "10.3.7",
+        "drupal/core": "10.3.x-dev",
         "asm89/stack-cors": "~v2.2.0",
         "composer/semver": "~3.4.0",
         "doctrine/annotations": "~1.14.3",
diff --git a/composer/Metapackage/PinnedDevDependencies/composer.json b/composer/Metapackage/PinnedDevDependencies/composer.json
index 59e550caedae5c4149f41e64159c9207df60fadb..3a7ac3aa522a515a35e4d24d789dcd47c4a5f868 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": "10.3.7",
+        "drupal/core": "10.3.x-dev",
         "behat/mink": "v1.11.0",
         "behat/mink-browserkit-driver": "v2.2.0",
         "colinodell/psr-testlogger": "v1.3.0",
diff --git a/composer/Template/LegacyProject/composer.json b/composer/Template/LegacyProject/composer.json
index fbd3bff2e0f6507afb9166079ec3ca677b213f28..da3bb1a0cb1540013457f5d98ef903dc4c433a85 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 d4908c029feb52d02be636e04bb6d90a6e7a5f86..4814912141eb755b79d7e734a7785582320d1126 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 687bd2991ebda36891e1df17b4a9c1b052331d16..4b150ba4e8c4a27e774ba11f155c2dd167f37d4e 100644
--- a/core/lib/Drupal.php
+++ b/core/lib/Drupal.php
@@ -75,7 +75,7 @@ class Drupal {
   /**
    * The current system version.
    */
-  const VERSION = '10.3.7';
+  const VERSION = '10.3.8-dev';
 
   /**
    * Core API compatibility.
diff --git a/core/lib/Drupal/Component/Annotation/composer.json b/core/lib/Drupal/Component/Annotation/composer.json
index 260122fb3fc468ffe5a27bdb72ba79c7cc684ba9..218e7b2fa8ea9c9762cf8ac0386617e9216fceb2 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": "^10.3",
-        "drupal/core-file-cache": "^10.3",
-        "drupal/core-plugin": "^10.3",
-        "drupal/core-utility": "^10.3"
+        "drupal/core-class-finder": "10.3.x-dev",
+        "drupal/core-file-cache": "10.3.x-dev",
+        "drupal/core-plugin": "10.3.x-dev",
+        "drupal/core-utility": "10.3.x-dev"
     },
     "autoload": {
         "psr-4": {
diff --git a/core/lib/Drupal/Component/Datetime/composer.json b/core/lib/Drupal/Component/Datetime/composer.json
index 1273120f6531ca80a249e280d9dd4cd0e3ab0d2b..c2391fb45a97bc00a5bc4ae6cb389eebf2013935 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": "^10.3"
+        "drupal/core-utility": "10.3.x-dev"
     },
     "autoload": {
         "psr-4": {
diff --git a/core/lib/Drupal/Component/Discovery/composer.json b/core/lib/Drupal/Component/Discovery/composer.json
index 490ca5d9a2dfaf92dbe56635f79513b2e4a14b29..758aef63450afb6a677f0501bda3dcb546d62da9 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": "^10.3",
-        "drupal/core-serialization": "^10.3"
+        "drupal/core-file-cache": "10.3.x-dev",
+        "drupal/core-serialization": "10.3.x-dev"
     },
     "autoload": {
         "psr-4": {
diff --git a/core/lib/Drupal/Component/FrontMatter/composer.json b/core/lib/Drupal/Component/FrontMatter/composer.json
index 6e1f333fb09607ab5f327214c2a4a046c92cbcc9..5ff2dc304eb4d3615275ecbb3a815e3e5b5fc5a5 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": "^10.3"
+        "drupal/core-serialization": "10.3.x-dev"
     },
     "autoload": {
         "psr-4": {
diff --git a/core/lib/Drupal/Component/Gettext/composer.json b/core/lib/Drupal/Component/Gettext/composer.json
index 4df1419f56a0d5bd7e72c4c4f6c48e25c6ed169b..61f297022976e690567909f0fa1a68b5651404e3 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": "^10.3"
+        "drupal/core-render": "10.3.x-dev"
     },
     "autoload": {
         "psr-4": {
diff --git a/core/lib/Drupal/Component/PhpStorage/composer.json b/core/lib/Drupal/Component/PhpStorage/composer.json
index 43a132ec1e3759262e96ba76d9f17d53a9a2dbe7..be4099a3367f876b79d38a1fc09f773f0b7995d2 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": "^10.3"
+        "drupal/core-file-security": "10.3.x-dev"
     },
     "autoload": {
         "psr-4": {
diff --git a/core/lib/Drupal/Component/Render/composer.json b/core/lib/Drupal/Component/Render/composer.json
index 641025399ccb289fcac1ee2255ce5cc59002dd1a..5b2d7738f0c30848e81f0f29d5bbc68b43c513b9 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": "^10.3"
+        "drupal/core-utility": "10.3.x-dev"
     },
     "autoload": {
         "psr-4": {