CVE-2025-53859

A memory access flaw has been discovered in nginx. The ngx_mail_smtp_module might allow an unauthenticated attacker to over-read NGINX SMTP authentication process memory. As a result, the server side may leak arbitrary bytes sent in a request to the authentication server. This issue occurs during the NGINX SMTP authentication process, requiring the attacker to prepare against the target system to extract the leaked data.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.