---
schema_version: '1.0'
id: security-20260705-c50ccf
url: https://osv.dev/vulnerability/DEBIAN-CVE-2025-53859
url_hash: c50ccf2ed6e4f7a34798308992df331913384f7eef35a56b557fb7a23ed13052
canonical_url: https://osv.dev/vulnerability/DEBIAN-CVE-2025-53859
source: osv:debian
category: security/os
category_raw: cve/os
region: null
tags:
- cve
- DEBIAN-CVE-2025-53859
- severity:CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- nginx
- Debian
lang: en
published_at: '2025-08-13T15:15:37Z'
fetched_at: '2026-07-05T15:34:33Z'
updated_at: '2026-07-05T15:34:52Z'
status: published
content_hash: aae26690c2956532a4fcae9f888a73708cd5d3342c5d41496b16196c72911e58
license_note: full
summary: 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 serv
summary_source: rss
summary_en: 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 serv
entities: []
key_facts: []
related: []
related_auto: []
title: DEBIAN-CVE-2025-53859 — nginx
---

# DEBIAN-CVE-2025-53859 — nginx

## TL;DR
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 serv

## Key Points
- cve / DEBIAN-CVE-2025-53859 / severity:CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X / nginx / Debian

## Details
**Severity:** CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
**Advisory:** DEBIAN-CVE-2025-53859

**Affected (your watchlist):**
- `Debian:nginx` 1.22.1-9+deb12u1 → no fixed version listed [proxmox]

**Details:**
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.

**References:**
- https://security-tracker.debian.org/tracker/CVE-2025-53859

_Data: OSV.dev (upstream: debian) — https://osv.dev/vulnerability/DEBIAN-CVE-2025-53859_

## Source
元記事: [DEBIAN-CVE-2025-53859 — nginx](https://osv.dev/vulnerability/DEBIAN-CVE-2025-53859) — published 2025-08-13T15:15:37Z