{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-33604", "assignerOrgId": "8ce71d90-2354-404b-a86e-bec2cc4e6981", "state": "PUBLISHED", "assignerShortName": "OX", "dateReserved": "2026-03-23T12:58:38.266Z", "datePublished": "2026-08-28T10:12:12.996Z", "dateUpdated": "2026-08-28T15:55:26.026Z"}, "containers": {"cna": {"affected": [{"defaultStatus": "unaffected", "modules": ["core"], "product": "OX Dovecot Pro", "vendor": "Open-Xchange GmbH", "versions": [{"lessThan": "2.3.22.2", "status": "affected", "version": "2.3.0", "versionType": "semver"}, {"lessThan": "3.0.7", "status": "affected", "version": "3.0.0", "versionType": "semver"}, {"lessThan": "3.1.6", "status": "affected", "version": "3.1.0", "versionType": "semver"}]}, {"defaultStatus": "unaffected", "modules": ["core"], "product": "OX Dovecot CE", "vendor": "Open-Xchange GmbH", "versions": [{"lessThan": "2.4.5", "status": "affected", "version": "2.3.0", "versionType": "semver"}]}], "descriptions": [{"lang": "en", "value": "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."}], "metrics": [{"cvssV3_1": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 5.9, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N", "version": "3.1"}, "format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "problemTypes": [{"descriptions": [{"cweId": "CWE-655", "description": "Insufficient Psychological Acceptability", "lang": "en", "type": "cwe"}]}], "providerMetadata": {"orgId": "8ce71d90-2354-404b-a86e-bec2cc4e6981", "shortName": "OX", "dateUpdated": "2026-08-28T10:30:33.647Z"}, "references": [{"tags": ["vendor-advisory"], "url": "https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0003.json"}], "source": {"defect": "DOV-8947", "discovery": "EXTERNAL"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-08-28T14:32:48.637127Z", "id": "CVE-2026-33604", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-08-28T15:55:26.026Z"}}]}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "modules": ["core"], "product": "OX Dovecot Pro", "vendor": "Open-Xchange GmbH", "versions": [{"lessThan": "2.3.22.2", "status": "affected", "version": "2.3.0", "versionType": "semver"}, {"lessThan": "3.0.7", "status": "affected", "version": "3.0.0", "versionType": "semver"}, {"lessThan": "3.1.6", "status": "affected", "version": "3.1.0", "versionType": "semver"}]}, {"defaultStatus": "unaffected", "modules": ["core"], "product": "OX Dovecot CE", "vendor": "Open-Xchange GmbH", "versions": [{"lessThan": "2.4.5", "status": "affected", "version": "2.3.0", "versionType": "semver"}]}], "source": "security@open-xchange.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "id": "CVE-2026-33604", "lastModified": "2026-08-28T12:16:27.613", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 5.9, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N", "version": "3.1"}, "exploitabilityScore": 2.2, "impactScore": 3.6, "source": "security@open-xchange.com", "type": "Secondary"}]}, "published": "2026-08-28T12:16:27.613", "references": [{"source": "security@open-xchange.com", "url": "https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0003.json"}], "sourceIdentifier": "security@open-xchange.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-655"}], "source": "security@open-xchange.com", "type": "Secondary"}]}

{}

{"created": "2026-08-28T12:45:02.924889+00:00", "title": "SMTP Smuggling via Dovecot Message Body Manipulation", "updated": "2026-08-28T12:45:02.924904+00:00", "vendors": []}