---
id: CVE-2026-42258
title: >-
  Net::IMAP implements Internet Message Access Protocol (IMAP) client
  functionality in Ruby
summary: >-
  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, symbol
  arguments to commands are vulnerable to a CRLF Injection / IMAP Command
  injection via Symbol a…
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:L'
cwe:
  - CWE-77
  - CWE-93
published: '2026-05-09'
updated: '2026-06-26'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-42258'
references:
  - url: 'https://github.com/ruby/net-imap/releases/tag/v0.4.24'
    label: security-advisories@github.com
  - url: 'https://github.com/ruby/net-imap/releases/tag/v0.5.14'
    label: security-advisories@github.com
  - url: 'https://github.com/ruby/net-imap/releases/tag/v0.6.4'
    label: security-advisories@github.com
  - url: 'https://github.com/ruby/net-imap/security/advisories/GHSA-75xq-5h9v-w6px'
    label: security-advisories@github.com
tags:
  - nvd
epss: 0.01253
epssPercentile: 0.68144
ingestedAt: '2026-06-29T13:24:34.840Z'
---

## Overview

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, symbol arguments to commands are vulnerable to a CRLF Injection / IMAP Command injection via Symbol arguments passed to IMAP commands. This issue has been patched in versions 0.4.24, 0.5.14, and 0.6.4.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.