Mailman 2.1.39 External Archiver Allows Unauth OS Command Exec via Subject
CVE-2025-43920 Published on April 20, 2025
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.
Weakness Type
What is a Shell injection Vulnerability?
The software constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.
CVE-2025-43920 has been classified to as a Shell injection vulnerability or weakness.
Products Associated with CVE-2025-43920
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Affected Versions
GNU Mailman Version 2.1.39 is affected by CVE-2025-43920Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.