{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-29143", "assignerOrgId": "455daabc-a392-441d-aa46-37d35189897c", "state": "PUBLISHED", "assignerShortName": "NCSC.ch", "dateReserved": "2026-03-04T09:08:07.342Z", "datePublished": "2026-04-02T08:49:31.012Z", "dateUpdated": "2026-04-02T13:34:31.668Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "455daabc-a392-441d-aa46-37d35189897c", "shortName": "NCSC.ch", "dateUpdated": "2026-04-02T08:49:31.012Z" }, "title": "S/MIME Decryption Impersonation", "problemTypes": [ { "descriptions": [ { "lang": "en", "cweId": "CWE-20", "description": "CWE-20 Improper Input Validation", "type": "CWE" } ] } ], "impacts": [ { "capecId": "CAPEC-43", "descriptions": [ { "lang": "en", "value": "CAPEC-43 Exploiting Multiple Input Interpretation Layers" } ] }, { "capecId": "CAPEC-194", "descriptions": [ { "lang": "en", "value": "CAPEC-194 Fake the Source of Data" } ] } ], "affected": [ { "vendor": "SEPPmail", "product": "Secure Email Gateway", "versions": [ { "status": "affected", "version": "0", "lessThan": "15.0.3", "versionType": "custom" } ], "defaultStatus": "unaffected" } ], "cpeApplicability": [ { "operator": "OR", "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:a:seppmail:seppmail_secure_email_gateway:*:*:*:*:*:*:*:*", "versionStartIncluding": "0", "versionEndExcluding": "15.0.3" } ] } ] } ], "descriptions": [ { "lang": "en", "value": "SEPPmail Secure Email Gateway before version 15.0.3 does not properly authenticate the inner message of S/MIME-encrypted MIME entities, allowing an attacker to control trusted headers.", "supportingMedia": [ { "type": "text/html", "base64": false, "value": "SEPPmail Secure Email Gateway before version 15.0.3 does not properly authenticate the inner message of S/MIME-encrypted MIME entities, allowing an attacker to control trusted headers." } ] } ], "references": [ { "url": "https://downloads.seppmail.com/extrelnotes/150/ERN15.0.html#seppmail-vulnerability-disclosure-1503", "tags": [ "release-notes" ] } ], "metrics": [ { "format": "CVSS", "scenarios": [ { "lang": "en", "value": "GENERAL" } ], "cvssV4_0": { "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "subConfidentialityImpact": "LOW", "vulnIntegrityImpact": "LOW", "subIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "version": "4.0", "baseSeverity": "HIGH", "baseScore": 7.8, "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:H/SA:N" } } ], "timeline": [ { "time": "2025-10-31T14:22:00.000Z", "lang": "en", "value": "Vulnerability disclosed to SEPPmail" }, { "time": "2026-03-03T00:00:00.000Z", "lang": "en", "value": "Version 15.0.3 released" } ], "credits": [ { "lang": "en", "value": "Andris Suter-Dörig", "type": "finder" }, { "lang": "en", "value": "Matteo Scarlata", "type": "coordinator" }, { "lang": "en", "value": "Kenny Paterson", "type": "coordinator" } ], "source": { "discovery": "EXTERNAL" }, "x_generator": { "engine": "Vulnogram 0.5.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "timestamp": "2026-04-02T13:34:22.865322Z", "id": "CVE-2026-29143", "options": [ { "Exploitation": "none" }, { "Automatable": "yes" }, { "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": "2026-04-02T13:34:31.668Z" } } ] } }