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CVE-2025-43921

MEDIUMCVSS 5.3/10EPSS 0.38%

Last modified

CVE-2025-43921 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. 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.. EPSS estimates a 0.38% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
5.3/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

EPSS Probability
0.38%

29.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
GnuMailman>= 2.1.1, <= 2.1.39

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2025-43921?
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.
How severe is CVE-2025-43921?
CVE-2025-43921 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 0.38% probability of exploitation in the next 30 days.
How do I fix CVE-2025-43921?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2025-43921?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST