{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-93647", "assignerOrgId": "9974b330-7714-4307-a722-5648477acda7", "state": "PUBLISHED", "assignerShortName": "rapid7", "dateReserved": "2026-09-18T12:22:43.194Z", "datePublished": "2026-09-25T13:58:05.368Z", "dateUpdated": "2026-09-26T03:55:48.781Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "9974b330-7714-4307-a722-5648477acda7", "shortName": "rapid7", "dateUpdated": "2026-09-25T13:58:05.368Z" }, "title": "Zimbra Collaboration Suite Classic Web Client Stored Cross-Site Scripting via Crafted Calendar COUNTER Message From Address", "datePublic": "2026-09-25T13:53:00.000Z", "problemTypes": [ { "descriptions": [ { "lang": "en", "cweId": "CWE-79", "description": "CWE-79 Improper neutralization of input during web page generation ('cross-site scripting')", "type": "CWE" } ] } ], "affected": [ { "vendor": "Zimbra", "product": "Zimbra Collaboration Suite (ZCS)", "versions": [ { "status": "affected", "version": "0", "lessThan": "10.1.21", "versionType": "semver" } ], "defaultStatus": "unaffected" } ], "descriptions": [ { "lang": "en", "value": "An unauthenticated calendar sender can place active markup in a COUNTER message's RFC From address. Selecting the message in Zimbra Classic triggers stored XSS, allowing the attacker to access mailbox data and act as the victim.", "supportingMedia": [ { "type": "text/html", "base64": false, "value": "An unauthenticated calendar sender can place active markup in a COUNTER message's RFC From address. Selecting the message in Zimbra Classic triggers stored XSS, allowing the attacker to access mailbox data and act as the victim." } ] } ], "references": [ { "url": "https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories", "tags": [ "vendor-advisory" ] } ], "metrics": [ { "format": "CVSS", "scenarios": [ { "lang": "en", "value": "GENERAL" } ], "cvssV3_1": { "version": "3.1", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "CHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "NONE", "baseSeverity": "CRITICAL", "baseScore": 9.3, "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N" } } ], "credits": [ { "lang": "en", "value": "Jonah Burgess (CryptoCat), Senior Security Researcher, Rapid7", "type": "finder" } ], "source": { "discovery": "UNKNOWN" }, "x_generator": { "engine": "Vulnogram 1.0.5" } }, "adp": [ { "title": "CISA ADP Vulnrichment", "metrics": [ { "other": { "type": "ssvc", "content": { "timestamp": "2026-09-25T00:00:00+00:00", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "role": "CISA Coordinator", "version": "2.0.3", "id": "CVE-2026-93647" } } } ], "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-09-26T03:55:48.781Z" } } ] } }