CVE-2025-43920
Publication date 20 April 2025
Last updated 2 March 2026
Ubuntu priority
Description
GNU Mailman 2.1.39, as bundled in cPanel (and WHM), in certain external archiver configurations, allows unauthenticated attackers to execute arbitrary OS commands via shell metacharacters in an email Subject line. NOTE: multiple third parties report that they are unable to reproduce this, regardless of whether cPanel or WHM is used.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| mailman | 25.10 questing | Not in release |
| 24.04 LTS noble | Not in release | |
| 22.04 LTS jammy | Not in release | |
| 20.04 LTS focal |
Not affected
|
|
| 18.04 LTS bionic |
Not affected
|
|
| 16.04 LTS xenial |
Not affected
|
Notes
john-breton
The mm_cfg.py file included with the versions of Mailman distributed in Ubuntu are not vulnerable. This appears to rely on code present only in the fork of Mailman supported by cPanel.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score |
5.4 · Medium
|
| Attack vector | Network |
| Attack complexity | High |
| Privileges required | None |
| User interaction | None |
| Scope | Changed |
| Confidentiality | Low |
| Integrity impact | Low |
| Availability impact | None |
| Vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N |