CVE-2025-27915
Synacor Zimbra Collaboration Suite (ZCS) Cross-site Scripting Vulnerability
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 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.
How to fix CVE-2025-27915
No package mapping is available — consult the references below for vendor-specific guidance.
Is CVE-2025-27915 being exploited?
Yes — CVE-2025-27915 is on the CISA Known Exploited Vulnerabilities (KEV) catalog. Patch immediately.
Affected packages (0)
No package mapping in OSV.