CVE-2026-42257
CRITICAL WAF: High
CVSS 9.8
Published: 2026-05-09
CWE-77
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.
WAF Coverage Analysis
Command Injection
High WAF Coverage
OWASP: A03:2021 Injection
932xxx - Remote Code Execution
Affected Software
| Vendor | Product | Version |
|---|---|---|
| ruby-lang | net\ | up to 0.4.24 |
| ruby-lang | net\ | 0.5.0 - 0.5.14 |
| ruby-lang | net\ | 0.6.0 - 0.6.4 |
References
- github.com (Release Notes)
- github.com (Release Notes)
- github.com (Release Notes)
- github.com (Mitigation, Vendor Advisory)