CVE-2026-33603

Name
CVE-2026-33603
Description
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.
NVD Severity
unknown
Other trackers
CVE, NVD, CERT, CVE Details, CIRCL, Arch Linux, Debian, Red Hat, Ubuntu, Gentoo, SUSE (Bugzilla), SUSE (CVE), Mageia
Mailing lists
oss-security, full-disclosure, bugtraq
Exploits
Exploit DB, Metasploit
Forges
GitHub (code, issues), Aports (code, issues)

References

Type URI
security@open-xchange.com https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0002.json

Match rules

CPE URI Source package Min version Max version
cpe:2.3:a:dovecot:dovecot:*:*:*:*:*:*:*:* dovecot >= None < 2.4.4
cpe:2.3:a:open-xchange:dovecot:*:*:*:*:pro:*:*:* dovecot >= None < 3.1.5

Vulnerable and fixed packages

Source package Branch Version Maintainer Status
dovecot edge-main 2.4.3-r1 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
dovecot edge-main 2.4.3-r0 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
dovecot edge-main 2.4.2-r2 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
dovecot edge-main 2.4.2-r1 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
dovecot edge-main 2.4.2-r0 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
dovecot edge-main 2.4.1-r3 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
dovecot edge-main 2.4.1-r2 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
dovecot edge-main 2.4.1-r1 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
dovecot edge-main 2.4.1-r0 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
dovecot edge-main 2.4.0-r1 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
dovecot edge-main 2.4.0-r0 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
dovecot edge-main 2.3.21.1-r0 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
dovecot edge-main 2.3.19.1-r6 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
dovecot edge-main 2.3.19.1-r5 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
dovecot edge-main 2.3.15-r0 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
dovecot edge-main 2.3.13-r0 None possibly vulnerable
dovecot edge-main 2.3.11.3-r0 None possibly vulnerable
dovecot edge-main 2.3.10.1-r0 None possibly vulnerable
dovecot edge-main 2.3.9.3-r0 None possibly vulnerable
dovecot edge-main 2.3.9.2-r0 None possibly vulnerable
dovecot edge-main 2.3.7.2-r0 None possibly vulnerable
dovecot edge-main 2.3.6-r0 None possibly vulnerable
dovecot edge-main 2.3.5.1-r0 None possibly vulnerable
dovecot edge-main 2.3.4.1-r0 None possibly vulnerable
dovecot edge-main 2.3.1-r0 None possibly vulnerable
dovecot 3.23-main 2.4.3-r1 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
dovecot 3.23-main 2.4.3-r0 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
dovecot 3.23-main 2.4.2-r1 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
dovecot 3.22-main 2.4.1-r2 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
dovecot 3.22-main 2.3.21.1-r0 None possibly vulnerable
dovecot 3.22-main 2.3.19.1-r5 None possibly vulnerable
dovecot 3.22-main 2.3.15-r0 None possibly vulnerable
dovecot 3.22-main 2.3.13-r0 None possibly vulnerable
dovecot 3.22-main 2.3.11.3-r0 None possibly vulnerable
dovecot 3.22-main 2.3.10.1-r0 None possibly vulnerable
dovecot 3.22-main 2.3.9.3-r0 None possibly vulnerable
dovecot 3.22-main 2.3.9.2-r0 None possibly vulnerable
dovecot 3.22-main 2.3.7.2-r0 None possibly vulnerable
dovecot 3.22-main 2.3.6-r0 None possibly vulnerable
dovecot 3.22-main 2.3.5.1-r0 None possibly vulnerable
dovecot 3.22-main 2.3.4.1-r0 None possibly vulnerable
dovecot 3.22-main 2.3.1-r0 None possibly vulnerable
dovecot 3.21-main 2.3.21.1-r0 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
dovecot 3.21-main 2.3.19.1-r5 None possibly vulnerable
dovecot 3.21-main 2.3.15-r0 None possibly vulnerable
dovecot 3.21-main 2.3.13-r0 None possibly vulnerable
dovecot 3.21-main 2.3.11.3-r0 None possibly vulnerable
dovecot 3.21-main 2.3.10.1-r0 None possibly vulnerable
dovecot 3.21-main 2.3.9.3-r0 None possibly vulnerable
dovecot 3.21-main 2.3.9.2-r0 None possibly vulnerable
dovecot 3.21-main 2.3.7.2-r0 None possibly vulnerable
dovecot 3.21-main 2.3.6-r0 None possibly vulnerable
dovecot 3.21-main 2.3.5.1-r0 None possibly vulnerable
dovecot 3.21-main 2.3.4.1-r0 None possibly vulnerable
dovecot 3.21-main 2.3.1-r0 None possibly vulnerable
dovecot 3.20-main 2.3.21.1-r0 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
dovecot 3.20-main 2.3.19.1-r5 None possibly vulnerable
dovecot 3.20-main 2.3.15-r0 None possibly vulnerable
dovecot 3.20-main 2.3.13-r0 None possibly vulnerable
dovecot 3.20-main 2.3.11.3-r0 None possibly vulnerable
dovecot 3.20-main 2.3.10.1-r0 None possibly vulnerable
dovecot 3.20-main 2.3.9.3-r0 None possibly vulnerable
dovecot 3.20-main 2.3.9.2-r0 None possibly vulnerable
dovecot 3.20-main 2.3.7.2-r0 None possibly vulnerable
dovecot 3.20-main 2.3.6-r0 None possibly vulnerable
dovecot 3.20-main 2.3.5.1-r0 None possibly vulnerable
dovecot 3.20-main 2.3.4.1-r0 None possibly vulnerable
dovecot 3.20-main 2.3.1-r0 None possibly vulnerable
dovecot 3.19-main 2.3.21-r17 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
dovecot 3.19-main 2.3.19.1-r5 None possibly vulnerable
dovecot 3.19-main 2.3.15-r0 None possibly vulnerable
dovecot 3.19-main 2.3.13-r0 None possibly vulnerable
dovecot 3.19-main 2.3.11.3-r0 None possibly vulnerable
dovecot 3.19-main 2.3.10.1-r0 None possibly vulnerable
dovecot 3.19-main 2.3.9.3-r0 None possibly vulnerable
dovecot 3.19-main 2.3.9.2-r0 None possibly vulnerable
dovecot 3.19-main 2.3.7.2-r0 None possibly vulnerable
dovecot 3.19-main 2.3.6-r0 None possibly vulnerable
dovecot 3.19-main 2.3.5.1-r0 None possibly vulnerable
dovecot 3.19-main 2.3.4.1-r0 None possibly vulnerable
dovecot 3.19-main 2.3.1-r0 None possibly vulnerable