CVE-2026-42258

Severity CVSS v4.0:

MEDIUM

Type:

CWE-77 Command Injection

Publication date:

09/05/2026

Last modified:

18/05/2026

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, 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.

Impact

Vector 4.0

CVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:P/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N CVSS v4.0 Severity and Metrics:

Base Score: 5.80 MEDIUM
Vector: CVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:P/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N

Attack Vector (AV): Local
Attack Complexity (AC): High
Attack Requirements (AT): Present
Privileges Required (PR): None
User Interaction (UI): Passsive
Confidentiality (VC): None
Integrity (VI): High
Availability (VA): Low
Confidentiality (SC): None
Integrity (SI): None
Availability (SA): None

Base Score 4.0

5.80

Severity 4.0

MEDIUM

Vector 3.x

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS v3.1 Severity and Metrics:

Base Score: 9.80 CRITICAL
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): High
Integrity (I): High
Availability (A): High

Base Score 3.x

9.80

Severity 3.x

CRITICAL

Vulnerable products and versions

CPE	From	Up to
cpe:2.3:a:ruby-lang:net\:\:imap::::::ruby::*		0.4.24 (excluding)
cpe:2.3:a:ruby-lang:net\:\:imap::::::ruby::*	0.5.0 (including)	0.5.14 (excluding)
cpe:2.3:a:ruby-lang:net\:\:imap::::::ruby::*	0.6.0 (including)	0.6.4 (excluding)

To consult the complete list of CPE names with products and versions, see this page

CVE-2026-42258

Description

Impact

Vulnerable products and versions

References to Advisories, Solutions, and Tools