CVE-2026-42257
Description
A flaw was found in Net::IMAP (before 0.4.24, 0.5.14, and 0.6.4). Several commands accept raw string arguments sent to the server without validation or escaping; if derived from user-controlled input, CRLF sequences allow injection of arbitrary IMAP commands.
Statement
Net::IMAP is vulnerable to IMAP command injection in versions before 0.4.24, 0.5.14, and 0.6.4. Several client commands accept raw string arguments that are sent to the IMAP server without CRLF validation or escaping; if application code passes user-controlled data into those arguments, an attacker can inject additional IMAP commands by embedding carriage return and line feed sequences. Red Hat impact is concentrated in Ruby-based products that bundle a vulnerable net-imap gem, including RHEL Ruby module streams, OpenShift Serverless (hummingbird) Ruby runtimes, and 3scale AMP components (zync/system) that use Net::IMAP with externally influenced input; Perl IMAP client packages on Fedora are a separate codebase and are not affected.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.1 | 9.8 | N/A |
| Attack Vector | Local | Network | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | None | None | N/A |
| User Interaction | Required | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | High | N/A |
| Integrity Impact | High | High | N/A |
| Availability Impact | Low | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:L
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Application Data
Frequently Asked Questions
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