CVE Alert: CVE-2025-53859
Vulnerability Summary: CVE-2025-53859
NGINX Open Source and NGINX Plus have a vulnerability in the ngx_mail_smtp_module that 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 happens during the NGINX SMTP authentication process and requires the attacker to make preparations against the target system to extract the leaked data. The issue affects NGINX only if (1) it is built with the ngx_mail_smtp_module, (2) the smtp_auth directive is configured with method “none,” and (3) the authentication server returns the “Auth-Wait” response header. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
Affected Endpoints:
No affected endpoints listed.
Published Date:
8/13/2025, 3:15:37 PM
❄️ CVSS Score:
Exploit Status:
Not ExploitedReferences:
Recommended Action:
No proposed action available. Please refer to vendor documentation for updates.
A considerable amount of time and effort goes into maintaining this website, creating backend automation and creating new features and content for you to make actionable intelligence decisions. Everyone that supports the site helps enable new functionality.
If you like the site, please support us on “Patreon” or “Buy Me A Coffee” using the buttons below
To keep up to date follow us on the below channels.
