CVE-2023-51766

mediumpriority · track · 21OT risk · elevatedEPSS 0.011 · 66 %ileDEEURUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

1.10% (66th) EPSS

CVSS 5.3 · medium

Is it mine?

24 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · scored 2026-10-27

Exim before 4.97.1 allows SMTP smuggling in certain PIPELINING/CHUNKING configurations. Remote attackers can use a published exploitation technique to inject e-mail messages with a spoofed MAIL FROM address, allowing bypass of an SPF protection mechanism. This occurs because Exim supports <LF>.<CR><LF> but some other popular e-mail servers do not.

cvss

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

6.5

010

base score 0–10 · higher = more severe · hover a vector to decode

v3.15.3mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:Nprimary · NVD / NIST USexploitability 3.9 · impact 1.4

v3.16.5mediumAV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:Nsecondary · FSTEC (BDU) RU

v3.14.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-345USprimaryCWE-77USCWE-924US

affected products (24)

Products and version ranges known to be affected.

Amazon Linux 2all versionscert_bundDEcpe:/o:amazon:linux_2:-
Debian Linuxall versionscert_bundDEcpe:/o:debian:debian_linux:-
Oracle Linuxall versionscert_bundDEcpe:/o:oracle:linux:-
RESF Rocky Linuxall versionscert_bundDEcpe:/o:resf:rocky_linux:-
Red Hat Enterprise Linuxall versionscert_bundDEcpe:/o:redhat:enterprise_linux:-
SUSE Linuxall versionscert_bundDEcpe:/o:suse:suse_linux:-
SUSE openSUSEall versionscert_bundDEcpe:/o:suse:opensuse:-
Open Source Dovecot< 2.4.5cert_bundDE
Open Source Open Source Dovecot <2.4.5< 2.4.5cert_bundDE
n/a n/a≤ n/aenisa_euvdEU
GNU General Public License exim≤ 4.97fstec_bduRU
АО «НППКТ» ОСОН ОСнова Оnyx≤ 2.10fstec_bduRU
ООО «Ред Софт» РЕД ОС≤ 7.3fstec_bduRU
ООО «РусБИТех-Астра» Astra Linux Common Edition≤ 1.6 «Смоленск»fstec_bduRU
ООО «РусБИТех-Астра» Astra Linux Special Edition≤ 1.8fstec_bduRU
ООО «РусБИТех-Астра» Astra Linux Special Edition≤ 4.7fstec_bduRU
ООО «РусБИТех-Астра» Astra Linux Special Edition≤ 1.7fstec_bduRU
debian debian linux= 10.0nvdUScpe:2.3:o:debian:debian_linux:*:*:*:*:*:*:*:*
exim exim< 4.97.1nvdUScpe:2.3:a:exim:exim:*:*:*:*:*:*:*:*
fedoraproject extra packages for enterprise linux= 7.0nvdUScpe:2.3:a:fedoraproject:extra_packages_for_enterprise_linux:*:*:*:*:*:*:*:*

showing 20 of 24

advisories (2)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2023-3206SMTP Implementierungen: Schwachstelle ermöglicht Umgehen von SicherheitsvorkehrungenDeutsch2023-12-21csaf · cert_bundDE
Ein entfernter, anonymer Angreifer kann eine Schwachstelle in verschiedenen SMTP Implementierungen ausnutzen, um Sicherheitsvorkehrungen zu umgehen.
WID-SEC-W-2026-3076Dovecot: Mehrere SchwachstellenDeutsch2026-08-27csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Dovecot ausnutzen, um Sicherheitsvorkehrungen zu umgehen, sensible Informationen offenzulegen, Daten zu manipulieren oder Denial-of-Service-Zustände herbeizuführen.

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu cert_bund nvd NVD CVE.org MITRE

published 2023-12-24modified 2026-06-17

related (1,449)

Related entries.

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+1444 more

references (61)

External citations — patches, advisories, analysis.

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