SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

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 commands via shell metacharacters in an email Subject line.

HIGH 8.1EPSS 0.56%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.56%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1
8.1 HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
0.56% probability · 45th percentile
CISA KEV
Not listed
Weakness
CWE-78
Affected
gnu/mailman
Source
cve@mitre.org

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.