Findings

Vulnerability · 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 metacha

Published Apr 20, 2025 · corrected/updated Apr 28, 2025 · GNU Mailman · evidence confidence high

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.

Grounded briefings

Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.

Executive

CVE-2025-43920 is a medium public vulnerability record for GNU Mailman. It is not currently listed in the CISA Known Exploited catalog. Check the linked vendor or CERT advisories for patch status. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.

System administrator

Identify whether GNU Mailman is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: GNU Mailman 2.1.39 (2.1.39). Check the linked vendor or CERT advisories for patch status. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.

Security analyst

Signals on file: CVSS 5.4, EPSS 59.0%. It is not currently listed in the CISA Known Exploited catalog. Sources contributing to this record: euvd. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.

Exploitation and remediation

  • Exploitation evidence

    Not listed as known exploited in CISA KEV. Not in CISA KEV or VulnCheck KEV.

  • Patch and remediation

    No required-action text is stored yet. Use the vendor or CERT links in Sources for patch availability.

  • Safe detection guidance

    Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Apr 20, 2025 · EUVD

    Detected

    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.

  2. Apr 28, 2025 · EUVD

    Updated

    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

  • vendor GNU Mailman 2.1.392.1.39

Sources

  • EUVDVulnerability recordEUVD-2025-12591

    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 reprod

    euvd.enisa.europa.eu

References