{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-66911", "assignerOrgId": "4bb8329e-dd38-46c1-aafb-9bf32bcb93c6", "state": "PUBLISHED", "assignerShortName": "CERT-PL", "dateReserved": "2026-07-28T12:14:18.398Z", "datePublished": "2026-10-29T15:22:19.086Z", "dateUpdated": "2026-10-29T15:22:19.086Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "4bb8329e-dd38-46c1-aafb-9bf32bcb93c6", "shortName": "CERT-PL", "dateUpdated": "2026-10-29T15:22:19.086Z"}, "title": "Stored Cross-Site Scripting in Zimbra", "problemTypes": [{"descriptions": [{"lang": "en", "cweId": "CWE-79", "description": "CWE-79 Improper neutralization of input during web page generation ('cross-site scripting')", "type": "CWE"}]}], "impacts": [{"capecId": "CAPEC-592", "descriptions": [{"lang": "en", "value": "CAPEC-592 Stored XSS"}]}], "affected": [{"vendor": "Synacor", "product": "Zimbra Collaboration", "versions": [{"status": "affected", "version": "0", "lessThan": "10.1.21", "versionType": "semver"}], "defaultStatus": "unaffected"}], "cpeApplicability": [{"operator": "OR", "nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:synacor:zimbra_collaboration:*:*:*:*:*:*:*:*", "versionStartIncluding": "0", "versionEndExcluding": "10.1.21"}]}]}], "descriptions": [{"lang": "en", "value": "Zimbra is vulnerable to stored cross-site scripting (XSS) via the Content-Location MIME header in email attachments. Due to lack of sanitization of the Content-Location header, an attacker can set it to a javascript: URI. An unauthenticated remote attacker can send a crafted email to a victim; when the victim opens the email in the Zimbra web interface and clicks the attachment name, the JavaScript payload executes in the victim's browser context.\u00a0This issue was fixed in version\u00a010.1.21", "supportingMedia": [{"type": "text/html", "base64": false, "value": "Zimbra is vulnerable to stored cross-site scripting (XSS) via the Content-Location MIME header in email attachments. Due to lack of sanitization of the Content-Location header, an attacker can set it to a javascript: URI. An unauthenticated remote attacker can send a crafted email to a victim; when the victim opens the email in the Zimbra web interface and clicks the attachment name, the JavaScript payload executes in the victim's browser context.&nbsp;<div>This issue was fixed in version&nbsp;<span>10.1.21</span></div>"}]}], "references": [{"url": "https://cert.pl/en/posts/2026/10/CVE-2026-66911", "tags": ["third-party-advisory"]}, {"url": "https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories", "tags": ["release-notes"]}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV4_0": {"attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "PASSIVE", "vulnConfidentialityImpact": "NONE", "subConfidentialityImpact": "LOW", "vulnIntegrityImpact": "NONE", "subIntegrityImpact": "LOW", "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": "MEDIUM", "baseScore": 5.3, "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N"}}], "credits": [{"lang": "en", "value": "Suraj Disoja (TrustFoundry)", "type": "finder"}, {"lang": "en", "value": "Mateusz Borkowski (CERT.PL)", "type": "finder"}], "source": {"discovery": "INTERNAL"}, "x_generator": {"engine": "Vulnogram 1.0.3"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Zimbra Collaboration", "vendor": "Synacor", "versions": [{"lessThan": "10.1.21", "status": "affected", "version": "0", "versionType": "semver"}]}], "source": "cvd@cert.pl"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Zimbra is vulnerable to stored cross-site scripting (XSS) via the Content-Location MIME header in email attachments. Due to lack of sanitization of the Content-Location header, an attacker can set it to a javascript: URI. An unauthenticated remote attacker can send a crafted email to a victim; when the victim opens the email in the Zimbra web interface and clicks the attachment name, the JavaScript payload executes in the victim's browser context.\u00a0This issue was fixed in version\u00a010.1.21"}], "id": "CVE-2026-66911", "lastModified": "2026-10-29T16:29:56.553", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 5.3, "baseSeverity": "MEDIUM", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "LOW", "subIntegrityImpact": "LOW", "userInteraction": "PASSIVE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "cvd@cert.pl", "type": "Secondary"}]}, "published": "2026-10-29T16:18:15.390", "references": [{"source": "cvd@cert.pl", "url": "https://cert.pl/en/posts/2026/10/CVE-2026-66911"}, {"source": "cvd@cert.pl", "url": "https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories"}], "sourceIdentifier": "cvd@cert.pl", "vulnStatus": "Awaiting Analysis", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-79"}], "source": "cvd@cert.pl", "type": "Primary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[0,10.1.21)"}}], "enrichment": {"confidence": 95.0, "confidence_source": "inferred", "scores": [{"score": 95.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Zimbra Collaboration", "source": "cna", "vendor": "Synacor"}, "product": "zimbra_collaboration", "vendor": "synacor"}], "created": "2026-10-29T17:30:14.526661+00:00", "updated": "2026-10-29T21:15:14.733892+00:00", "vendors": ["synacor", "synacor$PRODUCT$zimbra_collaboration"]}