{"schema":"threatline.record/2","record":{"id":"CVE-2025-27915","aliases":[],"summary":"Synacor Zimbra Collaboration Suite (ZCS) Cross-site Scripting Vulnerability","details":"Synacor Zimbra Collaboration Suite (ZCS) contains a cross-site scripting vulnerability that exists in the Classic Web Client due to insufficient sanitization of HTML content in ICS files. When a user views an e-mail message containing a malicious ICS entry, its embedded JavaScript executes via an ontoggle event inside a tag. This allows an attacker to run arbitrary JavaScript within the victim's session, potentially leading to unauthorized actions such as setting e-mail filters to redirect messages to an attacker-controlled address. As a result, an attacker can perform unauthorized actions on the victim's account, including e-mail redirection and data exfiltration.","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-2025-27915","source_modified_at":"2026-02-26T19:09:35.780Z","fetched_at":"2026-10-23T18:42:43.628194Z","product":"n/a","vendor":"n/a","versions":[{"version":"n/a","status":"affected"}],"defaultStatus":null}],"fixed_versions":[],"cvss":5.4,"severity":"Medium","kev":{"listed":true,"date_added":"2025-10-07","due_date":"2025-10-28","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":0.04064,"percentile":0.90627,"score_date":"2026-10-23"},"published_at":"2025-03-12T00:00:00.000Z","modified_at":"2026-02-26T19:09:35.780Z","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-2025-27915","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-02-26T19:09:35.780Z"},{"source":"Nuclei","url":"https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2025/CVE-2025-27915.yaml","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":null},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2025-27915","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CISA KEV","CVE List","Nuclei","EPSS"],"references":[{"source":"CVE List","url":"https://wiki.zimbra.com/wiki/Security_Center"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2025-27915","source":"CISA KEV"},{"source":"CVE List","url":"https://wiki.zimbra.com/wiki/Zimbra_Releases/10.1.5#Security_Fixes"},{"source":"CVE List","url":"https://wiki.zimbra.com/wiki/Zimbra_Releases/10.0.13#Security_Fixes"},{"source":"CVE List","url":"https://wiki.zimbra.com/wiki/Zimbra_Releases/9.0.0/P44#Security_Fixes"},{"source":"CVE List","url":"https://strikeready.com/blog/0day-ics-attack-in-the-wild/"},{"source":"CVE List","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-27915"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CISA ADP","ssvc":{"exploitation":"active","automatable":"no","technical_impact":"total","assessed_at":"2025-10-07T03:55:56.855156Z"},"exploits":[{"source":"Nuclei","kind":"Scanner template","name":"Zimbra - Cross-Site Scripting via ICS Files","url":"https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2025/CVE-2025-27915.yaml"}],"classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-02-26T19:09:35.780Z","content_hash":"19e2a8049b7137b72139b265a19df3b6fb92ff3ca00b9658c09ce17d644b3270"}}