ruby net-imap up to 0.4.23/0.5.13/0.6.3 Net::IMAP command injection

Summaryinfo

A vulnerability classified as critical was found in ruby net-imap up to 0.4.23/0.5.13/0.6.3. This affects the function Net::IMAP. Such manipulation leads to command injection. This vulnerability is traded as CVE-2026-42258. An attack has to be approached locally. There is no exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in ruby net-imap up to 0.4.23/0.5.13/0.6.3. It has been rated as critical. Affected by this issue is the function Net::IMAP. The manipulation with an unknown input leads to a command injection vulnerability. Using CWE to declare the problem leads to CWE-77. The product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component. Impacted is confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is available at github.com. This vulnerability is handled as CVE-2026-42258 since 04/26/2026. The exploitation is known to be difficult. Local access is required to approach this attack. Technical details are known, but there is no available exploit. This vulnerability is assigned to T1202 by the MITRE ATT&CK project.

The vulnerability scanner Nessus provides a plugin with the ID 323983 (RHEL 10 : ruby (RHSA-2026:33565)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 0.4.24, 0.5.14 or 0.6.4 eliminates this vulnerability. The upgrade is hosted for download at github.com.

The vulnerability is also documented in the databases at Tenable (323983) and CERT Bund (WID-SEC-2026-2117). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

• Red Hat Enterprise Linux
• RESF Rocky Linux
• HCL BigFix
• Oracle Linux

Productinfo

Type

• Programming Language Software

Vendor

• ruby

Name

• net-imap

Version

• 0.4.0
• 0.4.1
• 0.4.2
• 0.4.3
• 0.4.4
• 0.4.5
• 0.4.6
• 0.4.7
• 0.4.8
• 0.4.9
• 0.4.10
• 0.4.11
• 0.4.12
• 0.4.13
• 0.4.14
• 0.4.15
• 0.4.16
• 0.4.17
• 0.4.18
• 0.4.19
• 0.4.20
• 0.4.21
• 0.4.22
• 0.4.23
• 0.5.0
• 0.5.1
• 0.5.2
• 0.5.3
• 0.5.4
• 0.5.5
• 0.5.6
• 0.5.7
• 0.5.8
• 0.5.9
• 0.5.10
• 0.5.11
• 0.5.12
• 0.5.13
• 0.6.0
• 0.6.1
• 0.6.2
• 0.6.3

License

• open-source

Website

• Product: https://github.com/ruby/net-imap/

CPE 2.3info

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CPE 2.2info

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Entryinfo

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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