{
  "cvss": 7.2,
  "datePublished": "2026-03-18",
  "dateUpdated": "2026-03-18",
  "description": "Synacor Zimbra Collaboration Suite (ZCS) contains a cross-site scripting vulnerability in the Classic UI where attackers could abuse Cascading Style Sheets (CSS) @import directives in email HTML.",
  "dueDate": "2026-04-01",
  "id": "CVE-2025-66376",
  "kev_catalogs": [
    "cisa"
  ],
  "knownRansomwareCampaignUse": "Unknown",
  "notes": "https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories ; https://nvd.nist.gov/vuln/detail/CVE-2025-66376",
  "product": "Zimbra Collaboration Suite (ZCS)",
  "requiredAction": "Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.",
  "severity": "HIGH",
  "source": "cisa_known_exploited",
  "title": "Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting Vulnerability",
  "vendor": "Synacor"
}