CVE-2025-43921

Public Exploit

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.

Category

5.3
CVSS
Severity: Medium
CVSS 3.1 •
EPSS 0.05%
Third-Party Advisory github.com
Affected: GNU Mailman
Published at:
Updated at:

References

Link Tags
https://code.launchpad.net/~mailman-coders/mailman/2.1 product
https://github.com/0NYX-MY7H/CVE-2025-43921 third party advisory exploit
https://github.com/cpanel/mailman2-python3
https://www.openwall.com/lists/oss-security/2025/04/21/6

Frequently Asked Questions

What is the severity of CVE-2025-43921?
CVE-2025-43921 has been scored as a medium severity vulnerability.
How to fix CVE-2025-43921?
To fix CVE-2025-43921, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2025-43921 being actively exploited in the wild?
It is possible that CVE-2025-43921 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2025-43921?
CVE-2025-43921 affects GNU Mailman.
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