CVE-2025-43920: GNU Mailman 2.1.39, as bundled in cPanel (and WHM), in certain external archiver configurations, allows unauthenticated attackers to execute arbitrary OS…

PriorityP353high8.1CVSS 3.1

AVNACHPRNUINSUCHIHAH

EPSS

0.52%

40.7th percentile

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.

Affected

2 ranges

Vendor	Product	Version range	Fixed in
gnu	mailman	—	—
gnu	mailman	2.1.1 – 2.1.39	—

CVSS provenance

nvdv3.18.1HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

osv8.1HIGH

Stop checking back — get the weekly exploitation signal.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.