CVE-2025-53859
Published: Aug 13, 2025
Modified: Nov 4, 2025
CVSS v3.1
3.7
Description
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.
| Vendor | Product | Versions |
|---|---|---|
F5 | NGINX Plus | unaffected R35affected R34 - < R34 P2affected R33 - < R33 P3affected R32 - < R32 P3affected R31 - < *+1 more versions |
F5 | NGINX Open Source | affected 0.7 - < 1.29.1 |
Weaknesses (CWE)
CVSS v3.1 Details
CVSS v3.1 Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability
References
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