Arbitrary Command Injection Affecting ruby:3.3/ruby-libs package, versions <0:3.3.12-8.module_el8.10.0+4241+4264e34b


Severity

Recommended
high

Based on AlmaLinux security rating.

Threat Intelligence

EPSS
0.52% (42nd percentile)

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  • Snyk IDSNYK-ALMALINUX8-RUBY-19821712
  • published15 Sept 2026
  • disclosed5 Aug 2026

Introduced: 5 Aug 2026

CVE-2026-42257  (opens in a new tab)
CWE-77  (opens in a new tab)
CWE-93  (opens in a new tab)

How to fix?

Upgrade AlmaLinux:8 ruby:3.3/ruby-libs to version 0:3.3.12-8.module_el8.10.0+4241+4264e34b or higher.
This issue was patched in ALSA-2026:50728.

NVD Description

Note: Versions mentioned in the description apply only to the upstream ruby:3.3/ruby-libs package and not the ruby:3.3/ruby-libs package as distributed by AlmaLinux. See How to fix? for AlmaLinux:8 relevant fixed versions and status.

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, several Net::IMAP commands accept a raw string argument that is sent to the server without validation or escaping. If this string is derived from user-controlled input, it may contain contain CRLF sequences, which an attacker can use to inject arbitrary IMAP commands. This issue has been patched in versions 0.4.24, 0.5.14, and 0.6.4.

CVSS Base Scores

version 3.1