CVE-2025-43920

Name: CVE-2025-43920
Creator: NVD / NIST
Published: 2025-04-20T01:15:45.867+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.1/10EPSS 0.49%

Last modified Jun 17, 2026

CVE-2025-43920 is a high-severity vulnerability rated 8.1/10 on the CVSS scale. 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.. EPSS estimates a 0.49% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

8.1/10

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

EPSS Probability

0.49%

38.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Gnu	Mailman	>= 2.1.1, <= 2.1.39

References

https://code.launchpad.net/~mailman-coders/mailman/2.1Product
https://github.com/0NYX-MY7H/CVE-2025-43920Exploit, Third Party Advisory
https://github.com/cpanel/mailman2-python3
https://www.openwall.com/lists/oss-security/2025/04/21/6

Timeline

Published: Apr 20, 2025
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2025-43920?

How severe is CVE-2025-43920?

CVE-2025-43920 has a CVSS score of 8.1/10 (HIGH severity). The EPSS model estimates a 0.49% probability of exploitation in the next 30 days.

How do I fix CVE-2025-43920?

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-2025-43920?

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

Scan your code now

Source: NVD / NIST