{"dataType": "CVE_RECORD", "cveMetadata": {"state": "PUBLISHED", "cveId": "CVE-2026-33371", "assignerOrgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca", "assignerShortName": "mitre", "dateUpdated": "2026-03-23T13:39:46.789Z", "dateReserved": "2026-03-19T00:00:00.000Z", "datePublished": "2026-03-20T00:00:00.000Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca", "shortName": "mitre", "dateUpdated": "2026-03-20T14:09:04.967Z"}, "descriptions": [{"lang": "en", "value": "An issue was discovered in Zimbra Collaboration (ZCS) 10.0 and 10.1. An XML External Entity (XXE) vulnerability exists in the Zimbra Exchange Web Services (EWS) SOAP interface due to improper handling of XML input. An authenticated attacker can submit crafted XML data that is processed by an XML parser with external entity resolution enabled. Successful exploitation may allow disclosure of sensitive local files from the server."}], "affected": [{"vendor": "n/a", "product": "n/a", "versions": [{"version": "n/a", "status": "affected"}]}], "references": [{"url": "https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories"}, {"url": "https://wiki.zimbra.com/wiki/Security_Center"}, {"url": "https://wiki.zimbra.com/wiki/Zimbra_Responsible_Disclosure_Policy"}, {"url": "https://wiki.zimbra.com/wiki/Zimbra_Releases/10.1.16#Security_Fixes"}], "problemTypes": [{"descriptions": [{"type": "text", "lang": "en", "description": "n/a"}]}]}, "adp": [{"problemTypes": [{"descriptions": [{"type": "CWE", "cweId": "CWE-611", "lang": "en", "description": "CWE-611 Improper Restriction of XML External Entity Reference"}]}], "metrics": [{"cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 4.3, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "LOW", "confidentialityImpact": "LOW"}}, {"other": {"type": "ssvc", "content": {"timestamp": "2026-03-23T13:39:44.006410Z", "id": "CVE-2026-33371", "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": "2026-03-23T13:39:46.789Z"}}]}, "dataVersion": "5.2"}

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{"configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:synacor:zimbra_collaboration_suite:*:*:*:*:*:*:*:*", "matchCriteriaId": "E8DBE536-EAB0-48FF-A195-C0DB0A7FBCA0", "versionEndExcluding": "10.1.16", "versionStartIncluding": "10.0.0", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "An issue was discovered in Zimbra Collaboration (ZCS) 10.0 and 10.1. An XML External Entity (XXE) vulnerability exists in the Zimbra Exchange Web Services (EWS) SOAP interface due to improper handling of XML input. An authenticated attacker can submit crafted XML data that is processed by an XML parser with external entity resolution enabled. Successful exploitation may allow disclosure of sensitive local files from the server."}, {"lang": "es", "value": "Se descubri\u00f3 un problema en Zimbra Collaboration (ZCS) 10.0 y 10.1. Existe una vulnerabilidad de entidad externa XML (XXE) en la interfaz SOAP de Zimbra Exchange Web Services (EWS) debido a un manejo inadecuado de la entrada XML. Un atacante autenticado puede enviar datos XML manipulados que son procesados por un analizador XML con la resoluci\u00f3n de entidades externas habilitada. La explotaci\u00f3n exitosa puede permitir la divulgaci\u00f3n de archivos locales sensibles del servidor."}], "id": "CVE-2026-33371", "lastModified": "2026-04-01T15:35:47.497", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 4.3, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 1.4, "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}]}, "published": "2026-03-20T14:16:16.240", "references": [{"source": "cve@mitre.org", "tags": ["Vendor Advisory", "Release Notes"], "url": "https://wiki.zimbra.com/wiki/Security_Center"}, {"source": "cve@mitre.org", "tags": ["Release Notes"], "url": "https://wiki.zimbra.com/wiki/Zimbra_Releases/10.1.16#Security_Fixes"}, {"source": "cve@mitre.org", "tags": ["Product"], "url": "https://wiki.zimbra.com/wiki/Zimbra_Responsible_Disclosure_Policy"}, {"source": "cve@mitre.org", "tags": ["Vendor Advisory"], "url": "https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories"}], "sourceIdentifier": "cve@mitre.org", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-611"}], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[0,10.1]"}}], "enrichment": {"confidence": 100.0, "confidence_source": "manual", "scores": [{"score": 100.0, "source": "manual"}]}, "original": {"product": "n/a", "source": "cna", "vendor": "n/a"}, "product": "collaboration", "vendor": "zimbra"}], "analysis": {"en": {"generated_at": "2026-03-23T15:37:58.372574+00:00", "value": {"mitigation_remediation": ["Deploy Zimbra Collaboration version 10.1.16 or newer to apply the vendor\u2019s security fix", "If upgrading immediately is not feasible, temporarily disable external entity resolution in the XML parser used by the EWS service or block the EWS SOAP endpoint from external access", "Verify that only authorized accounts can access the EWS interface and review authentication settings", "Monitor server logs for suspicious XML payloads and alert on repeated malformed requests"], "summary": {"action": "Immediate Patch", "impact": "Confidentiality breach"}, "threat_synthesis": {"affected_systems": "Every deployment of Zimbra Collaboration version 10.0 or any 10.1 release is affected. The flaw exists specifically in the EWS SOAP endpoint that processes XML requests, and does not affect other Zimbra services. The latest security patch is available in version 10.1.16 and later, which mitigates the XXE problem.", "description_and_impact": "An XML External Entity (XXE) vulnerability is present in the Exchange Web Services (EWS) SOAP interface of Zimbra Collaboration 10.0 and 10.1. An authenticated attacker can submit crafted XML data that is parsed with external entity resolution enabled, allowing the server to read local files and disclose sensitive information. The flaw reveals a weakness in XML input handling (CWE\u2011611) and results in a confidentiality compromise rather than denial\u2011of\u2011service or code execution.", "risk_and_exploitability": "The CVSS score of 4.3 indicates moderate severity, while the EPSS score of less than 1\u202f% suggests a low likelihood of widespread exploitation. The vulnerability is not listed in the CISA KEV catalog and requires valid credentials to access the EWS interface, limiting the attack surface to authenticated users with sufficient privileges. Nonetheless, the ability to read internal files makes it a significant risk for organizations storing sensitive data on the same host."}}}}, "created": "2026-03-20T16:30:43.743943+00:00", "title": "XML External Entity Vulnerability in Zimbra Collaboration 10.0/10.1 EWS SOAP Interface", "updated": "2026-03-25T14:10:24.245315+00:00", "vendors": ["zimbra", "zimbra$PRODUCT$collaboration"]}