Create release for 4.0.3 (#3917)

* Create release for 4.0.3

* Write up the 4.0.3 release

---------

Co-authored-by: GitHub Actions Bot <github-actions[bot]@users.noreply.github.com>
Co-authored-by: Takashi Kokubun <takashikkbn@gmail.com>

Author: 3 people

_data/downloads.yml

@@ -7,7 +7,7 @@ preview:
 
 stable:
 
-  - 4.0.2
+  - 4.0.3
   - 3.4.9
   - 3.3.11
   - 3.2.11

_data/releases.yml

@@ -21,6 +21,30 @@
 
 # 4.0 series
 
+- version: 4.0.3
+  date: 2026-04-21
+  post: /en/news/2026/04/21/ruby-4-0-3-released/
+  url:
+    gz:  https://cache.ruby-lang.org/pub/ruby/4.0/ruby-4.0.3.tar.gz
+    zip: https://cache.ruby-lang.org/pub/ruby/4.0/ruby-4.0.3.zip
+    xz:  https://cache.ruby-lang.org/pub/ruby/4.0/ruby-4.0.3.tar.xz
+  size:
+    gz:  23806898
+    zip: 29109899
+    xz:  17878572
+  sha1:
+    gz:  619db0f25713a8f007d5889ae6e66ba0d31118e8
+    zip: d19d91723d7a19a34b860eee8544093f64c9d92f
+    xz:  faf1f3df171d2160116d190ca32b6b00e0338bfa
+  sha256:
+    gz:  77964acc370d5c8375b9502e5ba6c13c03ef91ab9eb9f521c84fb42b9c9a6b0f
+    zip: a80f1a3162950cfc1ef70f066132005efbb817f7ab6f16dcc244e5f015aabbc2
+    xz:  22cf6005d25bbe496b5ebe9224d63a1aaabfbfe02591bb5d612517c5a7836f29
+  sha512:
+    gz:  6fd12620869a9a36fa2e1cce302de42f429ab9e9fae1fe3b0901ca1a1b3a606a83feed87f4b76935beb715e8a750cf718f88afef2de4e866ad574b33abb12dbe
+    zip: 48b18fc578b5d7cd362a549ff5091c749d0460122f5dc3701fd6dada8016253fe0e85c498e20943e1a7f360b1e9fd073939da00df4b0c8a1afdddc16c43e43bc
+    xz:  5816fb264ce76df59f4bfe0cadceb45025fada2e61f2c14024d6b03f63d304820cddf94afcf82a4951fd12f3b0d9148683f856f3f2245d56042fc8407b6cbff5
+
 - version: 4.0.2
   date: 2026-03-16
   post: /en/news/2026/03/16/ruby-4-0-2-released/

en/news/_posts/2026-04-21-ruby-4-0-3-released.md

@@ -0,0 +1,50 @@
+---
+layout: news_post
+title: "Ruby 4.0.3 Released"
+author: k0kubun
+translator:
+date: 2026-04-21 08:45:44 +0000
+lang: en
+---
+
+Ruby 4.0.3 has been released.
+
+This release only contains ERB 6.0.1.1, which fixes [CVE-2026-41316](https://www.ruby-lang.org/en/news/2026/04/21/erb-cve-2026-41316/).
+
+If your application calls Marshal.load on untrusted data AND has both erb and activesupport loaded, please update your ERB to one of those versions. You can use this Ruby 4.0.3 release to do so.
+
+## Release Schedule
+
+We intend to release the latest stable Ruby version (currently Ruby 4.0) every two months following the most recent *regular* release. Ruby 4.0.4 will be released in May, 4.0.5 in July, 4.0.6 in September, and 4.0.7 in November.
+
+If a change arises that significantly affects users, a release may occur earlier than planned, and the subsequent schedule may shift accordingly.
+
+## Download
+
+{% assign release = site.data.releases | where: "version", "4.0.3" | first %}
+
+* <{{ release.url.gz }}>
+
+      SIZE: {{ release.size.gz }}
+      SHA1: {{ release.sha1.gz }}
+      SHA256: {{ release.sha256.gz }}
+      SHA512: {{ release.sha512.gz }}
+
+* <{{ release.url.xz }}>
+
+      SIZE: {{ release.size.xz }}
+      SHA1: {{ release.sha1.xz }}
+      SHA256: {{ release.sha256.xz }}
+      SHA512: {{ release.sha512.xz }}
+
+* <{{ release.url.zip }}>
+
+      SIZE: {{ release.size.zip }}
+      SHA1: {{ release.sha1.zip }}
+      SHA256: {{ release.sha256.zip }}
+      SHA512: {{ release.sha512.zip }}
+
+## Release Comment
+
+Many committers, developers, and users who provided bug reports helped us make this release.
+Thanks for their contributions.