Cool down before you install: give new gems a few days to be vetted

355 · Blog Rubygems · June 3, 2026, 3:18 a.m.
Summary
This blog post discusses the new 'cooldown' feature introduced in Bundler 4.0.13, which prevents the installation of newly released gems for a set period to mitigate the risk of supply-chain attacks. By utilizing a time-based filter, Bundler enhances security by ensuring that gems are not installed until they have been publicly available long enough to be scrutinized. The post details how to configure cooldown settings on gem sources and discusses its integration with other security practices on RubyGems.