CVE-2026-33604
Summary
| CVE | CVE-2026-33604 |
|---|---|
| State | PUBLISHED |
| Assigner | OX |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-08-28 12:16:27 UTC |
| Updated | 2026-08-28 20:17:25 UTC |
| Description | An attacker that can get Dovecot to relay a message, for example through Sieve redirect or submission relay, can use a crafted line ending in the message body to bypass the outbound protection that prevents message content from being interpreted as SMTP commands. A downstream mail server that hasn't yet fixed the SMTP smuggling vulnerability can be tricked into treating part of the message body as new SMTP commands, allowing injection of spoofed email. This is the same vulnerability class as CVE-2023-51764 and CVE-2023-51766. Where you control the receiving mail servers, ensure they reject bare carriage returns in message data. Update to non-vulnerable version. No publicly available exploits are known. |
Risk And Classification
Primary CVSS: v3.1 5.9 MEDIUM from [email protected]
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
Problem Types: CWE-655 | CWE-655 Insufficient Psychological Acceptability
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 5.9 | MEDIUM | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N |
| 3.1 | CNA | CVSS | 5.9 | MEDIUM | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
HighPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
HighAvailability
NoneCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Open-Xchange GmbH | OX Dovecot Pro | affected 2.3.0 2.3.22.2 semver | Not specified |
| CNA | Open-Xchange GmbH | OX Dovecot Pro | affected 3.0.0 3.0.7 semver | Not specified |
| CNA | Open-Xchange GmbH | OX Dovecot Pro | affected 3.1.0 3.1.6 semver | Not specified |
| CNA | Open-Xchange GmbH | OX Dovecot CE | affected 2.3.0 2.4.5 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0003.json | [email protected] | documentation.open-xchange.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.