CVE-2026-42245 (Medium) detected in net-imap-0.6.3.gem

[mend-bolt-for-github]

CVE-2026-42245 - Medium Severity Vulnerability

Vulnerable Library - net-imap-0.6.3.gem

Ruby client api for Internet Message Access Protocol

Library home page: https://rubygems.org/gems/net-imap-0.6.3.gem

Path to dependency file: /Gemfile.lock

Path to vulnerable library: /vendor/cache/net-imap-0.6.3.gem

Dependency Hierarchy:

• rails-8.0.5.gem (Root Library)
  • actionmailer-8.0.5.gem
    • mail-2.9.0.gem
      • ❌ net-imap-0.6.3.gem (Vulnerable Library)

Found in base branch: master

Vulnerability Details

Net::IMAP implements Internet Message Access Protocol (IMAP) client functionality in Ruby. Prior to versions 0.4.24, 0.5.14, and 0.6.4, Net::IMAP::ResponseReader has quadratic time complexity when reading large responses containing many string literals. A hostile server can send responses which are crafted to exhaust the client's CPU for a denial of service attack. This issue has been patched in versions 0.4.24, 0.5.14, and 0.6.4.

Publish Date: 2026-05-09

URL: CVE-2026-42245

CVSS 3 Score Details (4.3)

Base Score Metrics:

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

For more information on CVSS3 Scores, click here.

Suggested Fix

Type: Upgrade version

Origin: GHSA-q2mw-fvj9-vvcw

Release Date: 2026-05-05

Fix Resolution: net-imap - 0.5.14,https://github.com/ruby/net-imap.git - v0.4.24,https://github.com/ruby/net-imap.git - v0.5.14,https://github.com/ruby/net-imap.git - v0.6.4,net-imap - 0.6.4,net-imap - 0.4.24

---

Step up your Open Source Security Game with Mend here