{"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": "2026-09-25T13:58:05.368Z"}, "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\u00a0From\u00a0address. 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&nbsp;<code>From</code>&nbsp;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"}}}}