{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-93633",
        "assignerOrgId": "9974b330-7714-4307-a722-5648477acda7",
        "state": "PUBLISHED",
        "assignerShortName": "rapid7",
        "dateReserved": "2026-09-18T12:22:34.911Z",
        "datePublished": "2026-10-23T13:25:21.365Z",
        "dateUpdated": "2026-10-23T13:25:21.365Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "9974b330-7714-4307-a722-5648477acda7",
                "shortName": "rapid7",
                "dateUpdated": "2026-10-23T13:25:21.365Z"
            },
            "title": "Zimbra Collaboration Suite Briefcase CSS Sanitization Bypass via Non-ASCII Stylesheet Characters",
            "datePublic": "2026-10-23T12:54:00.000Z",
            "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",
                    "versions": [
                        {
                            "status": "affected",
                            "version": "0",
                            "lessThanOrEqual": "10.1.20",
                            "versionType": "semver"
                        }
                    ],
                    "defaultStatus": "unaffected"
                }
            ],
            "descriptions": [
                {
                    "lang": "en",
                    "value": "A CSS sanitization vulnerability in Zimbra Collaboration Suite (ZCS) allows an authenticated user with Briefcase access to publish a document that displays attacker-controlled content under the Zimbra origin. When processing a stylesheet containing non-ASCII characters, DefangFilter appends the final ASCII segment without sanitizing it. HTML stored as application/x-zimbra-doc can therefore retain CSS URL references that the normal sanitizer removes. An attacker can share a crafted document that loads external resources and displays a credential-collection form using Zimbra's own visual assets. Exploitation requires the victim to open the document in a browser that renders the content type inline; credential theft additionally requires form submission. ZCS 10.1.16 and 10.1.20 are affected.",
                    "supportingMedia": [
                        {
                            "type": "text/html",
                            "base64": false,
                            "value": "A CSS sanitization vulnerability in Zimbra Collaboration Suite (ZCS) allows an authenticated user with Briefcase access to publish a document that displays attacker-controlled content under the Zimbra origin. When processing a stylesheet containing non-ASCII characters, DefangFilter appends the final ASCII segment without sanitizing it. HTML stored as application/x-zimbra-doc can therefore retain CSS URL references that the normal sanitizer removes. An attacker can share a crafted document that loads external resources and displays a credential-collection form using Zimbra's own visual assets. Exploitation requires the victim to open the document in a browser that renders the content type inline; credential theft additionally requires form submission. ZCS 10.1.16 and 10.1.20 are affected."
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories",
                    "tags": [
                        "vendor-advisory"
                    ]
                },
                {
                    "url": "https://www.rapid7.com/blog/post/ve-breaking-zimbra-identity-boundaries-part-1/",
                    "tags": [
                        "related"
                    ]
                }
            ],
            "metrics": [
                {
                    "format": "CVSS",
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "GENERAL"
                        }
                    ],
                    "cvssV3_1": {
                        "version": "3.1",
                        "attackVector": "NETWORK",
                        "attackComplexity": "LOW",
                        "privilegesRequired": "LOW",
                        "userInteraction": "REQUIRED",
                        "scope": "CHANGED",
                        "confidentialityImpact": "LOW",
                        "integrityImpact": "LOW",
                        "availabilityImpact": "NONE",
                        "baseSeverity": "MEDIUM",
                        "baseScore": 5.4,
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/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"
            }
        }
    }
}