RubyGems Adds Bundler Cooldown to Delay New Gem Installs by Days
Updated
Updated · InfoWorld · Jun 5
RubyGems Adds Bundler Cooldown to Delay New Gem Installs by Days
1 articles · Updated · InfoWorld · Jun 5
Summary
Bundler now lets Ruby developers ignore newly published gem versions for a user-set number of days, adding a cooling-off period before updates are installed.
The change targets supply-chain attacks that hijack maintainer credentials, slip malicious code into package updates, and then steal more credentials from developers who install them.
Bundler enforces the delay by checking each gem version's publish timestamp, steering installs to older releases until newer ones have had time to be vetted.
Known-good emergency fixes can still bypass the wait, balancing the new safeguard against the need to quickly patch serious security flaws.
With AI now creating 'sleeper' malware, can a simple time delay truly secure the software supply chain against sophisticated, patient attackers?
As AI generates both exploits and defenses, is open-source software entering an endless, automated cybersecurity arms race?
RubyGems Cooldown: A 1-Hour Buffer Against Software Supply Chain Threats
Overview
In April 2026, RubyGems and Bundler introduced the 'cooldown' security feature in versions 4.0.13, marking a major step in protecting the Ruby ecosystem. This proactive defense works by using the created_at timestamp from rubygems.org to delay the installation of newly published gem versions. When a new gem is released, the cooldown mechanism temporarily holds it back, creating a critical window to identify and address potential malicious activity before a compromised gem can spread. By strategically delaying updates, the cooldown feature helps mitigate software supply chain risks and strengthens overall security for developers.