Bug 2388238 (CVE-2025-53859) - CVE-2025-53859 nginx: NGINX ngx_mail_smtp_module vulnerability
Summary: CVE-2025-53859 nginx: NGINX ngx_mail_smtp_module vulnerability
Keywords:
Status: NEW
Alias: CVE-2025-53859
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
low
low
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On: 2388410 2388411
Blocks:
TreeView+ depends on / blocked
 
Reported: 2025-08-13 15:01 UTC by OSIDB Bzimport
Modified: 2025-08-14 14:31 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:

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Description OSIDB Bzimport 2025-08-13 15:01:36 UTC 
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.
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