CVE-2025-53859

lowpriority · track · 0EPSS 0.004 · 35 %ileDEEURUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

0.41% (35th) EPSS

CVSS 3.7 · low

Is it mine?

32 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · fstec_bdu · osv

EPSS · scored 2026-10-27

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.

cvss

Technical severity, 0–10. One row per scoring source.

6.3

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–medium · 1.7–6.3

v3.13.7lowAV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:Nsecondary · FSTEC (BDU) RU

v3.13.7lowCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:Nsecondary · f5sirt@f5.comexploitability 2.2 · impact 1.4

v4.06.3mediumCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:Nsecondary · ENISA EU

v4.06.3mediumCVSS: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:Xsecondary · f5sirt@f5.com

v4.01.7lowCVSS: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:U/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:Xsecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Trackcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-125USCWE-125US

affected products (32)

Products and version ranges known to be affected.

IBM DB2all versionscert_bundDEcpe:/a:ibm:db2:-
Red Hat Enterprise Linuxall versionscert_bundDEcpe:/o:redhat:enterprise_linux:-
Splunk SOAR< 8.6.0cert_bundDE
F5 NGINX Open Source0.7 → 1.29.1enisa_euvdEU
F5 NGINX PlusR30 → *enisa_euvdEU
F5 NGINX PlusR31 → *enisa_euvdEU
F5 NGINX PlusR32 → R32 P3enisa_euvdEU
F5 NGINX PlusR33 → R33 P3enisa_euvdEU
F5 NGINX PlusR34 → R34 P2enisa_euvdEU
NGINX Inc. NGINX Open Source0.7 → 1.29.1fstec_bduRU
NGINX Inc. NGINX Plus≤ R30fstec_bduRU
NGINX Inc. NGINX Plus≤ R31fstec_bduRU
NGINX Inc. NGINX PlusR32 → R32 P3fstec_bduRU
NGINX Inc. NGINX PlusR33 → R33 P3fstec_bduRU
NGINX Inc. NGINX PlusR34 → R34 P2fstec_bduRU
АО «ИВК» АЛЬТ СП 10all versionsfstec_bduRU
АО «ИВК» Альт 8 СПall versionsfstec_bduRU
АО «НППКТ» ОСОН ОСнова Оnyx≤ 3.1fstec_bduRU
АО «СберТех» Platform V SberLinux OS Server≤ 9.2.0-fstecfstec_bduRU
АО «СберТех» Platform V SynGX≤ 3.2.0-fstecfstec_bduRU

showing 20 of 32

advisories (4)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2025-1817NGINX: Schwachstelle ermöglicht Offenlegung von InformationenDeutsch2025-08-13csaf · cert_bundDE
Ein entfernter, anonymer Angreifer kann eine Schwachstelle in NGINX und NGINX NGINX Plus ausnutzen, um Informationen offenzulegen.
WID-SEC-W-2026-2933Splunk SOAR: Mehrere SchwachstellenDeutsch2026-08-19csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Splunk SOAR ausnutzen, um Sicherheitsvorkehrungen zu umgehen, um Informationen offenzulegen, um Dateien zu manipulieren, um einen SQL-Injection Angriff durchzuführen, um einen Cross-Site Scripting Angriff durchzuführen, und um beliebigen Programmcode auszuführen.
BIT-nginx-2025-53859NGINX ngx_mail_smtp_module vulnerability2025-08-18vendor · osvUS
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.
BIT-nginx-gateway-2025-53859NGINX ngx_mail_smtp_module vulnerability2025-12-03vendor · osvUS
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.

also known as (7)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu osv cert_bund NVD CVE.org MITRE

published 2025-08-13modified 2026-06-17

references (6)

External citations — patches, advisories, analysis.

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