Vulnerability 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.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Gnu | Mailman | >= 2.1.1, <= 2.1.39 |
Related Weaknesses (CWE)
References
- https://code.launchpad.net/~mailman-coders/mailman/2.1Product
- https://github.com/0NYX-MY7H/CVE-2025-43920ExploitThird Party Advisory
- https://github.com/cpanel/mailman2-python3
- https://www.openwall.com/lists/oss-security/2025/04/21/6
FAQ
What is CVE-2025-43920?
CVE-2025-43920 is a vulnerability with a CVSS score of 5.4 (MEDIUM). 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 ...
How severe is CVE-2025-43920?
CVE-2025-43920 has been rated MEDIUM with a CVSS base score of 5.4/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-43920?
Check the references section above for vendor advisories and patch information. Affected products include: Gnu Mailman.