CVE-2025-27915 — Actively Exploited: Zimbra Collaboration Suite (ZCS) (Synacor)
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
| CVE ID | CVE-2025-27915 |
|---|---|
| Vendor | Synacor |
| Product | Zimbra Collaboration Suite (ZCS) |
| Vulnerability name | Synacor Zimbra Collaboration Suite (ZCS) Cross-site Scripting Vulnerability |
| Date added | 2025-10-07 |
| Remediation due | 2025-10-28 |
| Known ransomware use | Unknown |
| 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. |
| Description | 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 s |
| Source | CISA Known Exploited Vulnerabilities |
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