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CVE-2025-43920: mailman vulnerability
CVE-2025-43920: medium vulnerability affecting mailman. Check CVSS, KEV status, business impact and recommended administrator actions.
- CVSS
- 5.4 MEDIUM
- EPSS
- 43.43%
- Known exploited
- not in KEV
- Product
- mailman
What is known
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.
Business impact
Successful exploitation of CVE-2025-43920, a medium vulnerability (CVSS 5.4) affecting mailman, may affect the confidentiality, integrity or availability of the vulnerable environment. The exact impact depends on the installed version, exposed interfaces and deployment configuration.
Recommended administrator action
Confirm whether mailman is present and compare installed versions with the vendor advisory and NVD record. Apply the vendor patch or documented mitigation; until remediation is complete, reduce exposure of affected interfaces, review relevant logs and monitor for indicators of exploitation. DataHouse can support version verification, managed patching, network exposure reduction, log review and backup validation for dedicated, cloud and colocated environments.