Vulnerability Description
GNU Mailman 2.1.39, as bundled in cPanel (and WHM), allows unauthenticated attackers to create lists via the /mailman/create endpoint. 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-2025-43921ExploitThird Party Advisory
- https://github.com/cpanel/mailman2-python3
- https://www.openwall.com/lists/oss-security/2025/04/21/6
FAQ
What is CVE-2025-43921?
CVE-2025-43921 is a vulnerability with a CVSS score of 5.3 (MEDIUM). GNU Mailman 2.1.39, as bundled in cPanel (and WHM), allows unauthenticated attackers to create lists via the /mailman/create endpoint. NOTE: multiple third parties report that they are unable to repro...
How severe is CVE-2025-43921?
CVE-2025-43921 has been rated MEDIUM with a CVSS base score of 5.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-43921?
Check the references section above for vendor advisories and patch information. Affected products include: Gnu Mailman.