diff --git a/composer.lock b/composer.lock
index c1b46050b45510cc5a633af543b843bf1f8cd8a9..8b6e887354daa9ddf88d8fcd10698cb32f9252f3 100644
--- a/composer.lock
+++ b/composer.lock
@@ -491,7 +491,7 @@
         },
         {
             "name": "drupal/core",
-            "version": "10.3.x-dev",
+            "version": "10.3.0-rc1",
             "dist": {
                 "type": "path",
                 "url": "core",
@@ -652,7 +652,7 @@
         },
         {
             "name": "drupal/core-project-message",
-            "version": "10.3.x-dev",
+            "version": "10.3.0-rc1",
             "dist": {
                 "type": "path",
                 "url": "composer/Plugin/ProjectMessage",
@@ -685,7 +685,7 @@
         },
         {
             "name": "drupal/core-vendor-hardening",
-            "version": "10.3.x-dev",
+            "version": "10.3.0-rc1",
             "dist": {
                 "type": "path",
                 "url": "composer/Plugin/VendorHardening",
@@ -9608,11 +9608,7 @@
     ],
     "aliases": [],
     "minimum-stability": "dev",
-    "stability-flags": {
-        "drupal/core": 20,
-        "drupal/core-project-message": 20,
-        "drupal/core-vendor-hardening": 20
-    },
+    "stability-flags": [],
     "prefer-stable": true,
     "prefer-lowest": false,
     "platform": [],
@@ -9620,5 +9616,5 @@
     "platform-overrides": {
         "php": "8.1.0"
     },
-    "plugin-api-version": "2.6.0"
+    "plugin-api-version": "2.3.0"
 }
diff --git a/composer/Metapackage/CoreRecommended/composer.json b/composer/Metapackage/CoreRecommended/composer.json
index d47a031ae3773399dc8faf8e94ff21c1bb6e29d4..8c6953bfef343ffffda2d700d33b48304a59bab4 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.x-dev",
+        "drupal/core": "10.3.0-rc1",
         "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 b75a06197de55dfb50f750cf708dbb52f59ab702..1b7086b6e1dcfb126d25a004102e50fa2bb83f6a 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.x-dev",
+        "drupal/core": "10.3.0-rc1",
         "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 da3bb1a0cb1540013457f5d98ef903dc4c433a85..941a6d852489a5a640b1a73eece45a92b82cfb4d 100644
--- a/composer/Template/LegacyProject/composer.json
+++ b/composer/Template/LegacyProject/composer.json
@@ -27,7 +27,7 @@
     "conflict": {
         "drupal/drupal": "*"
     },
-    "minimum-stability": "dev",
+    "minimum-stability": "RC",
     "prefer-stable": true,
     "config": {
         "allow-plugins": {
diff --git a/composer/Template/RecommendedProject/composer.json b/composer/Template/RecommendedProject/composer.json
index 4814912141eb755b79d7e734a7785582320d1126..c8c68ccf54e3dcaa5a2a83b9aa514eff4747e74b 100644
--- a/composer/Template/RecommendedProject/composer.json
+++ b/composer/Template/RecommendedProject/composer.json
@@ -26,7 +26,7 @@
     "conflict": {
         "drupal/drupal": "*"
     },
-    "minimum-stability": "dev",
+    "minimum-stability": "RC",
     "prefer-stable": true,
     "config": {
         "allow-plugins": {
diff --git a/core/lib/Drupal.php b/core/lib/Drupal.php
index 4ca937b6c68d30d0fe03d04c316b35c07a890302..dcd6676ddf0d07e9d22288f35914c8b9398e3827 100644
--- a/core/lib/Drupal.php
+++ b/core/lib/Drupal.php
@@ -75,7 +75,7 @@ class Drupal {
   /**
    * The current system version.
    */
-  const VERSION = '10.3.0-dev';
+  const VERSION = '10.3.0-rc1';
 
   /**
    * Core API compatibility.
diff --git a/core/lib/Drupal/Component/Annotation/composer.json b/core/lib/Drupal/Component/Annotation/composer.json
index 218e7b2fa8ea9c9762cf8ac0386617e9216fceb2..748da4929d10cd9d6e0f68e3ff44b76f6d2e40fb 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.x-dev",
-        "drupal/core-file-cache": "10.3.x-dev",
-        "drupal/core-plugin": "10.3.x-dev",
-        "drupal/core-utility": "10.3.x-dev"
+        "drupal/core-class-finder": "10.3.0-rc1",
+        "drupal/core-file-cache": "10.3.0-rc1",
+        "drupal/core-plugin": "10.3.0-rc1",
+        "drupal/core-utility": "10.3.0-rc1"
     },
     "autoload": {
         "psr-4": {
@@ -24,5 +24,5 @@
             "This file was partially generated automatically. See: https://www.drupal.org/node/3293830"
         ]
     },
-    "minimum-stability": "dev"
+    "minimum-stability": "RC"
 }
diff --git a/core/lib/Drupal/Component/Datetime/composer.json b/core/lib/Drupal/Component/Datetime/composer.json
index c2391fb45a97bc00a5bc4ae6cb389eebf2013935..0f4e09e0ebf39230ebdde1d8d8611c4ebf96e8ba 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.x-dev"
+        "drupal/core-utility": "10.3.0-rc1"
     },
     "autoload": {
         "psr-4": {
@@ -20,5 +20,5 @@
             "This file was partially generated automatically. See: https://www.drupal.org/node/3293830"
         ]
     },
-    "minimum-stability": "dev"
+    "minimum-stability": "RC"
 }
diff --git a/core/lib/Drupal/Component/Discovery/composer.json b/core/lib/Drupal/Component/Discovery/composer.json
index 758aef63450afb6a677f0501bda3dcb546d62da9..ae3554efba1ba9907f5fb7978e6b20fdf4113b88 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.x-dev",
-        "drupal/core-serialization": "10.3.x-dev"
+        "drupal/core-file-cache": "10.3.0-rc1",
+        "drupal/core-serialization": "10.3.0-rc1"
     },
     "autoload": {
         "psr-4": {
@@ -21,5 +21,5 @@
             "This file was partially generated automatically. See: https://www.drupal.org/node/3293830"
         ]
     },
-    "minimum-stability": "dev"
+    "minimum-stability": "RC"
 }
diff --git a/core/lib/Drupal/Component/FrontMatter/composer.json b/core/lib/Drupal/Component/FrontMatter/composer.json
index 5ff2dc304eb4d3615275ecbb3a815e3e5b5fc5a5..ad34c9dd6ab3b1b6aa02ce51ae6f3181bf0fb99d 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.x-dev"
+        "drupal/core-serialization": "10.3.0-rc1"
     },
     "autoload": {
         "psr-4": {
@@ -20,5 +20,5 @@
             "This file was partially generated automatically. See: https://www.drupal.org/node/3293830"
         ]
     },
-    "minimum-stability": "dev"
+    "minimum-stability": "RC"
 }
diff --git a/core/lib/Drupal/Component/Gettext/composer.json b/core/lib/Drupal/Component/Gettext/composer.json
index 61f297022976e690567909f0fa1a68b5651404e3..d8be6ce236d6801b8f47b1087853d74ee9139ac8 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.x-dev"
+        "drupal/core-render": "10.3.0-rc1"
     },
     "autoload": {
         "psr-4": {
@@ -21,5 +21,5 @@
             "This file was partially generated automatically. See: https://www.drupal.org/node/3293830"
         ]
     },
-    "minimum-stability": "dev"
+    "minimum-stability": "RC"
 }
diff --git a/core/lib/Drupal/Component/PhpStorage/composer.json b/core/lib/Drupal/Component/PhpStorage/composer.json
index be4099a3367f876b79d38a1fc09f773f0b7995d2..8ec6a4a787dfa146ecedd246495a3e1cadeb3aaf 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.x-dev"
+        "drupal/core-file-security": "10.3.0-rc1"
     },
     "autoload": {
         "psr-4": {
@@ -20,5 +20,5 @@
             "This file was partially generated automatically. See: https://www.drupal.org/node/3293830"
         ]
     },
-    "minimum-stability": "dev"
+    "minimum-stability": "RC"
 }
diff --git a/core/lib/Drupal/Component/Render/composer.json b/core/lib/Drupal/Component/Render/composer.json
index 5b2d7738f0c30848e81f0f29d5bbc68b43c513b9..a3102831193f64f5d899dbc4ec70c61d8bf3ce73 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.x-dev"
+        "drupal/core-utility": "10.3.0-rc1"
     },
     "autoload": {
         "psr-4": {
@@ -20,5 +20,5 @@
             "This file was partially generated automatically. See: https://www.drupal.org/node/3293830"
         ]
     },
-    "minimum-stability": "dev"
+    "minimum-stability": "RC"
 }