{"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":"2026-10-28T19:51:07.972Z"},"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"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-28T17:48:57.736632Z","id":"CVE-2026-93633","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":"2026-10-28T19:51:07.972Z"}}]}}