CVE-2026-34763 (Medium) detected in rack-3.1.16.gem

Vulnerable Library - rack-3.1.16.gem

Rack provides a minimal, modular and adaptable interface for developing web applications in Ruby. By wrapping HTTP requests and responses in the simplest way possible, it unifies and distills the API for web servers, web frameworks, and software in between (the so-called middleware) into a single method call.

Library home page: https://rubygems.org/gems/rack-3.1.16.gem

Path to dependency file: /Gemfile.lock

Path to vulnerable library: /vendor/cache/rack-3.1.16.gem

Dependency Hierarchy:

• manageiq-style-1.3.3.gem (Root Library)
  • rubocop-rails-2.32.0.gem
    • ❌ rack-3.1.16.gem (Vulnerable Library)

Found in base branch: master

Vulnerability Details

Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, Rack::Directory interpolates the configured root path directly into a regular expression when deriving the displayed directory path. If root contains regex metacharacters such as +, *, or ., the prefix stripping can fail and the generated directory listing may expose the full filesystem path in the HTML output. This issue has been patched in versions 2.2.23, 3.1.21, and 3.2.6.

Publish Date: 2026-04-02

URL: CVE-2026-34763

CVSS 3 Score Details (5.3)

Base Score Metrics:

• Exploitability Metrics:
  • Attack Vector: Network
  • Attack Complexity: Low
  • Privileges Required: None
  • User Interaction: None
  • Scope: Unchanged
• Impact Metrics:
  • Confidentiality Impact: Low
  • Integrity Impact: None
  • Availability Impact: None

Suggested Fix

Type: Upgrade version

Origin: https://github.com/advisories/GHSA-7mqq-6cf9-v2qp

Release Date: 2026-04-02

Fix Resolution: rack - 3.2.6,rack - 2.2.23,rack - 3.1.21