CVE-2023-27582: Maddy Project Maddy

Critical severity, CVSS 9.8. EPSS: 1% chance of exploitation in the next 30 days.

maddy is a composable, all-in-one mail server. Starting with version 0.2.0 and prior to version 0.6.3, maddy allows a full authentication bypass if SASL authorization username is specified when using the PLAIN authentication mechanisms. Instead of validating the specified username, it is accepted as is after checking the credentials for the authentication username. maddy 0.6.3 includes the fix for the bug. There are no known workarounds.

Affected products

• Maddy Project Maddy: from 0.2.0, before 0.6.3 (fixed in 0.6.3)

Published 2023-03-13. Last modified 2026-06-17.