CVE-2026-42258
ruby/net-imap: ruby: Net::IMAP: IMAP Command Injection via Symbol Arguments
Severity
ImportantRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · May 10, 2026
Updated · September 1, 2026
Description
A flaw was found in Net::IMAP, a Ruby library that provides Internet Message Access Protocol (IMAP) client functionality. This vulnerability allows a remote attacker to inject arbitrary IMAP commands. This is achieved by passing specially crafted symbol arguments to IMAP commands. Successful exploitation could lead to unauthorized actions on the IMAP server or client, potentially resulting in information disclosure or other integrity impacts.
Statement
This command injection flaw is limited to the injection of IMAP commands. Arbitrary code execution is not a risk of this flaw and so the impact is limited to email systems.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
CVSS / CWE
CVSS 3.1 · 7.1CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:N
CWE-93 · Improper Neutralization of CRLF Sequences ('CRLF Injection')