CVE-2026-42257: CWE-93: Improper Neutralization of CRLF Sequences ('CRLF Injection') in ruby net-imap
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.
AI Analysis
Technical Summary
The Ruby net-imap library implements IMAP client functionality. Versions before 0.4.24, 0.5.14, and 0.6.4 accept raw string arguments in several IMAP commands without sanitizing CRLF sequences. If these strings come from user input, an attacker can inject CRLF sequences to manipulate or inject arbitrary IMAP commands. This vulnerability is classified as CWE-93 (Improper Neutralization of CRLF Sequences) and CWE-77 (Improper Neutralization of Special Elements used in a Command). The vulnerability has been addressed by patches in the specified versions.
Potential Impact
An attacker able to supply crafted input to vulnerable versions of net-imap can inject arbitrary IMAP commands by exploiting improper neutralization of CRLF sequences. This can lead to manipulation of IMAP protocol interactions, potentially affecting the integrity of client-server communication. The CVSS 4.0 base score is 5.8 (medium severity), reflecting local attack vector with partial attack complexity and partial user interaction required, and high impact on integrity and low on availability and confidentiality.
Mitigation Recommendations
This vulnerability has been patched in net-imap versions 0.4.24, 0.5.14, and 0.6.4. Users should upgrade to at least these versions to remediate the issue. No vendor advisory was provided to indicate alternative mitigations or temporary fixes. Patch status is confirmed by the version information in the description.
CVE-2026-42257: CWE-93: Improper Neutralization of CRLF Sequences ('CRLF Injection') in ruby net-imap
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.
CVSS v4.0
Score 5.8medium
Affected software
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Ruby net-imap library implements IMAP client functionality. Versions before 0.4.24, 0.5.14, and 0.6.4 accept raw string arguments in several IMAP commands without sanitizing CRLF sequences. If these strings come from user input, an attacker can inject CRLF sequences to manipulate or inject arbitrary IMAP commands. This vulnerability is classified as CWE-93 (Improper Neutralization of CRLF Sequences) and CWE-77 (Improper Neutralization of Special Elements used in a Command). The vulnerability has been addressed by patches in the specified versions.
Potential Impact
An attacker able to supply crafted input to vulnerable versions of net-imap can inject arbitrary IMAP commands by exploiting improper neutralization of CRLF sequences. This can lead to manipulation of IMAP protocol interactions, potentially affecting the integrity of client-server communication. The CVSS 4.0 base score is 5.8 (medium severity), reflecting local attack vector with partial attack complexity and partial user interaction required, and high impact on integrity and low on availability and confidentiality.
Mitigation Recommendations
This vulnerability has been patched in net-imap versions 0.4.24, 0.5.14, and 0.6.4. Users should upgrade to at least these versions to remediate the issue. No vendor advisory was provided to indicate alternative mitigations or temporary fixes. Patch status is confirmed by the version information in the description.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-04-26T11:53:27.704Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69ff93c0cbff5d86106e4595
Added to database: 05/09/2026, 20:06:24 UTC
Last enriched: 05/17/2026, 09:33:17 UTC
Last updated: 07/31/2026, 19:22:58 UTC
Views: 121
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