RubyGems 4.0.18 and Bundler 4.0.18 security update

{
  "id": "b248d524e3ae165eb9a0c9252d7e4f0130d0bbd2f95c404de310d28b5e1b9776",
  "url": "https://github.com/ruby/rubygems/releases/tag/v4.0.18",
  "method": "llm",
  "payload": {
    "kind": "patch",
    "title": "RubyGems 4.0.18 and Bundler 4.0.18 security update",
    "summary": "The release adds a `--cooldown` flag to `bundle lock` and `bundle cache`.",
    "evidence": "Security: Add --cooldown flag to bundle lock and bundle cache.",
    "products": [
      {
        "name": {
          "value": "Bundler",
          "evidence": "Bundler 4.0.18"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "4.0.18",
            "evidence": "Bundler 4.0.18"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "fixed_cves": [],
    "related_cves": [],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "github-rubygems-rubygems",
  "document_id": 22528,
  "published_at": "2026-09-17T22:00:18+00:00"
}