CVE-2020-5239: Mailu

High severity, CVSS 8.8. EPSS: 0.9% chance of exploitation in the next 30 days.

In Mailu before version 1.7, an authenticated user can exploit a vulnerability in Mailu fetchmail script and gain full access to a Mailu instance. Mailu servers that have open registration or untrusted users are most impacted. The master and 1.7 branches are patched on our git repository. All Docker images published on docker.io/mailu for tags 1.5, 1.6, 1.7 and master are patched. For detailed instructions about patching and securing the server afterwards, see https://github.com/Mailu/Mailu/issues/1354

Affected products

• Mailu Mailu: before 1.7 (fixed in 1.7)

Published 2020-02-13. Last modified 2026-06-17.