Added 4.0.3 release announcement

Author: hsbt

_posts/2025-12-23-4.0.3-released.md

@@ -0,0 +1,55 @@
+---
+title: 4.0.3 Released
+layout: post
+author: Hiroshi SHIBATA
+author_email: hsbt@ruby-lang.org
+---
+
+RubyGems 4.0.3 includes enhancements and documentation and Bundler 4.0.3 includes enhancements.
+
+To update to the latest RubyGems you can run:
+
+    gem update --system [--pre]
+
+To update to the latest Bundler you can run:
+
+    gem install bundler [--pre]
+    bundle update --bundler=4.0.3
+
+## RubyGems Release Notes
+
+
+### Enhancements:
+
+* Installs bundler 4.0.3 as a default gem.
+
+### Documentation:
+
+* Fix broken documentation links. Pull request
+  [#9208](https://github.com/ruby/rubygems/pull/9208) by eileencodes
+
+
+## Bundler Release Notes
+
+
+### Enhancements:
+
+  - Fall back to ruby platform gem when precompiled variant is incompatible [#9211](https://github.com/ruby/rubygems/pull/9211)
+
+
+## Manual Installation
+
+To install RubyGems by hand see the [Download RubyGems][download] page.
+
+SHA256 Checksums:
+
+* rubygems-4.0.3.tgz  
+  f5f728a40603773eec1a5c0857693485e7a118619f6ae70dcece6c2e719129a0
+* rubygems-4.0.3.zip  
+  2b8c02560ed846e7e007564a97ef2d1c5b6f77d1f957ed4d4e5635a3083a83b7
+* rubygems-update-4.0.3.gem  
+  eeb62154c557a5750f28a30e7361b7d333631db6178cd4ccafe7b3361ffdbb1e
+
+
+[download]: https://rubygems.org/pages/download
+