CVE-2026-42257

net-imap: Command Injection via "raw" arguments to multiple commands

State: Published
Severity: 5.8 Medium
Published: May 9, 2026
Updated: May 13, 2026
Reserved: Apr 26, 2026

Description

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.

Scores

CVSS	Score	Vector	Source
4.0	5.8 Medium	CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:P/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N	GitHub_M

Weaknesses

CWE-93 Improper Neutralization of CRLF Sequences ('CRLF Injection')
CWE-77 Improper Neutralization of Special Elements used in a Command ('Command Injection')

Affected Products

Product	Versions
net-imapruby	< 0.4.24Affected >= 0.5.0, < 0.5.14Affected >= 0.6.0, < 0.6.4Affected

References

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.