CVE-2026-42257 PUBLISHED

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

Assigner: GitHub_M
Reserved: 26.04.2026 Published: 09.05.2026 Updated: 09.05.2026

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.

Metrics

CVSS 4.0

CVSS Vector: 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
CVSS Score: 5.8

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Local	Confidentiality	None	Confidentiality	None
Attack Complexity	Low	Integrity	High	Integrity	None
Attack Requirements	Present	Availability	Low	Availability	None
Privileges Required	None
User Interaction	Passive

CVSS 4.0

Product Status

Vendor	ruby
Product	net-imap
Versions	Version < 0.4.24 is affected Version >= 0.5.0, < 0.5.14 is affected Version >= 0.6.0, < 0.6.4 is affected

References

Problem Types

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