# Ruby 4.0.5 — Ruby 4.0.5 Released

- Product: Ruby (https://whatsnew.fyi/product/ruby)
- Vendor: Ruby
- Date: 2026-05-20
- Version: 4.0.5
- Original notes: https://www.ruby-lang.org/en/news/2026/05/20/ruby-4-0-5-released/
- Permalink: https://whatsnew.fyi/product/ruby/releases/4.0.5

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Ruby 4.0.5 has been released. This release only contains a security fix for CVE-2026-46727: Use-after-free in pthread-based getaddrinfo timeout handler and a build system regression in Ruby 4.0.4 unde…

- **security** — Fix use-after-free in pthread-based getaddrinfo timeout handler (CVE-2026-46727)
- **fixed** — Fix build system regression from Ruby 4.0.4