{"id":"CVE-2025-66376","title":"Zimbra Collaboration (ZCS) 10 before 10.0.18 and 10.1 before 10.1.13 allows Classic UI stored XSS via Cascading Style Sheets (CSS) @import directives in an HTML e-mail message.","summary":"Zimbra Collaboration (ZCS) 10 before 10.0.18 and 10.1 before 10.1.13 allows Classic UI stored XSS via Cascading Style Sheets (CSS) @import directives in an HTML e-mail message.","severity":"high","cvss":7.2,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N","cwe":["CWE-79"],"vendor":"synacor","product":"zimbra_collaboration_suite","affected":["zimbra_collaboration_suite >= 10.0.0, < 10.0.18","zimbra_collaboration_suite >= 10.1.0, < 10.1.13"],"patched":["zimbra_collaboration_suite 10.1.13"],"published":"2026-01-05","updated":"2026-09-30","sourceUpdated":"2026-09-30T23:10:00.237","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2025-66376","references":[{"url":"https://wiki.zimbra.com/wiki/Security_Center","label":"cve@mitre.org"},{"url":"https://wiki.zimbra.com/wiki/Zimbra_Releases/10.0.18#Security_Fixes","label":"cve@mitre.org"},{"url":"https://wiki.zimbra.com/wiki/Zimbra_Releases/10.1.13#Security_Fixes","label":"cve@mitre.org"},{"url":"https://wiki.zimbra.com/wiki/Zimbra_Responsible_Disclosure_Policy","label":"cve@mitre.org"},{"url":"https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories","label":"cve@mitre.org"},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-66376","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"tags":["nvd","kev","in-the-wild"],"epss":0.19559,"epssPercentile":0.97303,"kev":true,"kevDateAdded":"2026-03-18","kevDueDate":"2026-04-01","kevRansomware":false,"exploited":true,"ingestedAt":"2026-09-30T23:29:32.540Z","slug":"CVE-2025-66376","body":"## Overview\n\nZimbra Collaboration (ZCS) 10 before 10.0.18 and 10.1 before 10.1.13 allows Classic UI stored XSS via Cascading Style Sheets (CSS) @import directives in an HTML e-mail message.\n\n## Affected\n\n- `zimbra_collaboration_suite >= 10.0.0, < 10.0.18`\n- `zimbra_collaboration_suite >= 10.1.0, < 10.1.13`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `zimbra_collaboration_suite 10.1.13`","depth":"abyssal","depthScore":69,"depthScoreParts":{"impact":39.6,"likelihood":3.9,"exploitation":25,"ransomware":0},"changes":[]}