{"schema":"threatline.record/2","record":{"id":"CVE-2025-66376","aliases":[],"summary":"Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting Vulnerability","details":"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.","categories":["Applications & CMS"],"product":"Zimbra Collaboration Suite (ZCS)","vendor":"Synacor","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2025-66376","source_modified_at":"2026-03-19T03:55:17.926Z","fetched_at":"2026-10-23T18:42:43.628194Z","product":"Collaboration","vendor":"Zimbra","versions":[{"lessThan":"10.0.18","status":"affected","version":"10.0","versionType":"custom"},{"lessThan":"10.1.13","status":"affected","version":"10.1","versionType":"custom"}],"defaultStatus":"unaffected"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2025-66376","source_modified_at":"2026-03-19T03:55:17.926Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"name":"Collaboration","ecosystem":null},"version":"10.0.18","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2025-66376","source_modified_at":"2026-03-19T03:55:17.926Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"name":"Collaboration","ecosystem":null},"version":"10.1.13","basis":"first unaffected version stated in the CVE record"}],"cvss":7.2,"severity":"High","kev":{"listed":true,"date_added":"2026-03-18","due_date":"2026-04-01","required_action":"Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.","ransomware_campaign_use":"Unknown"},"epss":{"probability":0.20227,"percentile":0.97465,"score_date":"2026-10-23"},"published_at":"2026-01-05T00:00:00.000Z","modified_at":"2026-03-19T03:55:17.926Z","provenance":[{"source":"CISA KEV","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23T17:00:09.9001Z"},{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2025-66376","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-03-19T03:55:17.926Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2025-66376","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CISA KEV","CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2025-66376","source":"CISA KEV"},{"source":"CVE List","url":"https://wiki.zimbra.com/wiki/Security_Center"},{"source":"CVE List","url":"https://wiki.zimbra.com/wiki/Zimbra_Responsible_Disclosure_Policy"},{"source":"CVE List","url":"https://wiki.zimbra.com/wiki/Zimbra_Releases/10.1.13#Security_Fixes"},{"source":"CVE List","url":"https://wiki.zimbra.com/wiki/Zimbra_Releases/10.0.18#Security_Fixes"},{"source":"CVE List","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-66376","tags":["government-resource"]}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","ssvc":{"exploitation":"active","automatable":"no","technical_impact":"partial","assessed_at":"2026-03-17T00:00:00+00:00"},"classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-03-19T03:55:17.926Z","content_hash":"5bb6f383fdc93da6bb7e9a0b9b69ee8847c39f76f5ad84805e74cf000a3661de"}}