CVE-2026-42257
Publication date 9 May 2026
Last updated 2 June 2026
Ubuntu priority
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.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| ruby2.5 | 26.04 LTS resolute | Not in release |
| 25.10 questing | Not in release | |
| 24.04 LTS noble | Not in release | |
| 22.04 LTS jammy | Not in release | |
| 18.04 LTS bionic |
Vulnerable
|
|
| ruby2.3 | 26.04 LTS resolute | Not in release |
| 25.10 questing | Not in release | |
| 24.04 LTS noble | Not in release | |
| 22.04 LTS jammy | Not in release | |
| 16.04 LTS xenial |
Needs evaluation
|
|
| ruby2.7 | 26.04 LTS resolute | Not in release |
| 25.10 questing | Not in release | |
| 24.04 LTS noble | Not in release | |
| 22.04 LTS jammy | Not in release | |
| 20.04 LTS focal |
Needs evaluation
|
|
| ruby3.0 | 26.04 LTS resolute | Not in release |
| 25.10 questing | Not in release | |
| 24.04 LTS noble | Not in release | |
| 22.04 LTS jammy |
Needs evaluation
|
|
| ruby3.2 | 26.04 LTS resolute | Not in release |
| 25.10 questing | Not in release | |
| 24.04 LTS noble |
Needs evaluation
|
|
| 22.04 LTS jammy | Not in release | |
| ruby3.3 | 26.04 LTS resolute |
Needs evaluation
|
| 25.10 questing |
Needs evaluation
|
|
| 24.04 LTS noble | Not in release | |
| 22.04 LTS jammy | Not in release | |
| jruby | 26.04 LTS resolute |
Needs evaluation
|
| 25.10 questing |
Needs evaluation
|
|
| 24.04 LTS noble |
Needs evaluation
|
|
| 22.04 LTS jammy | Not in release | |
| 20.04 LTS focal |
Needs evaluation
|
|
| 18.04 LTS bionic |
Needs evaluation
|
|
| 16.04 LTS xenial | Ignored end of ESM support, was needs-triage | |
| 14.04 LTS trusty |
Needs evaluation
|
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score |
9.8 · Critical
|
| Attack vector | Network |
| Attack complexity | Low |
| Privileges required | None |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality | High |
| Integrity impact | High |
| Availability impact | High |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |