Authentication Bypass Vulnerability in Dovecot by Open-Xchange

CVE-2026-24031

What is CVE-2026-24031?

An authentication bypass vulnerability exists in Dovecot SQL authentication, where an administrator can inadvertently disable the 'auth_username_chars' configuration. This misconfiguration allows attackers to bypass authentication checks, potentially enabling unauthorized access and user enumeration. It is crucial for administrators to avoid clearing 'auth_username_chars'; if this cannot be prevented, they should promptly upgrade to the latest patched version to mitigate risks.

References