CVE-2026-33603

mediumpriority · track · 21EPSS 0.002 · 12 %ileDEEURUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

0.21% (12th) EPSS

CVSS 5.3 · medium

Is it mine?

28 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · scored 2026-10-27

Attacker can use a specially crafted base64 exchange between Dovecot and Client to fake SCRAM TLS channel binding. This requires that the attacker is able to position itself between Dovecot and the client connection. If successful, the attacker can eavesdrop communications between Dovecot and client as MITM proxy. Install fixed version. No publicly available exploits are known.

cvss

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

6.8

010

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

v3.15.3mediumCVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:Nprimary · NVD / NIST USexploitability 1.6 · impact 3.6

v3.15.3mediumAV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Lsecondary · FSTEC (BDU) RU

v3.16.8mediumCVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:Nsecondary · ENISA EU

v3.16.8mediumCVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:Nsecondary · security@open-xchange.comexploitability 1.6 · impact 5.2

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

ssvc

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

Exploitation: none · Automatable: no · Technical Impact: totalcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-99USCWE-99US

affected products (28)

Products and version ranges known to be affected.

Debian Linuxall versionscert_bundDEcpe:/o:debian:debian_linux:-
Fedora Linuxall versionscert_bundDEcpe:/o:fedoraproject:fedora:-
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:-
Ubuntu Linuxall versionscert_bundDEcpe:/o:canonical:ubuntu_linux:-
Open Source Dovecot≤ OX Pro core <2.4.4cert_bundDE
Open Source Dovecot≤ OX Pro core <3.1.5cert_bundDE
cPanel cPanel/WHM< 110.0.138cert_bundDE
cPanel cPanel/WHM< 137.9999.96cert_bundDE
Open-Xchange GmbH OX Dovecot Pro≤ 0 ≤2.4.0enisa_euvdEU
Open-Xchange GmbH OX Dovecot Pro≤ 0 ≤3.1.0enisa_euvdEU
Open-Xchange OX Dovecot Pro≤ 3.1.5fstec_bduRU
Red Hat, Inc. Red Hat Enterprise Linux≤ 8fstec_bduRU
Red Hat, Inc. Red Hat Enterprise Linux≤ 10fstec_bduRU
Red Hat, Inc. Red Hat Enterprise Linux≤ 9fstec_bduRU
Red Hat, Inc. Red Hat Enterprise Linux≤ 6fstec_bduRU
Timo Sirainen Dovecot≤ 2.4.4fstec_bduRU

showing 20 of 28

advisories (1)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2026-1510OX Dovecot Pro: Mehrere SchwachstellenDeutsch2026-05-12csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in OX Dovecot Pro ausnutzen, um SQL-Injection-Angriffe durchzuführen, Sicherheitsmaßnahmen zu umgehen, Daten zu manipulieren oder offenzulegen oder einen Denial-of-Service-Zustand zu verursachen.

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 CVE.org MITRE

published 2026-05-12modified 2026-10-26

references (4)

External citations — patches, advisories, analysis.

scry

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