https://pwn.watch/i/synacor-zimbra-collaboration-suite-zcs-cve-2025-27915 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. Added to CISA KEV on 2025-10-07. en Tue, 07 Oct 2025 00:00:00 GMT https://pwn.watch/i/synacor-zimbra-collaboration-suite-zcs-cve-2025-27915 https://pwn.watch/i/synacor-zimbra-collaboration-suite-zcs-cve-2025-27915#2025-10-07-e2ec6eb3 Tue, 07 Oct 2025 00:00:00 GMT medium <p>Synacor Zimbra Collaboration Suite (ZCS): Zimbra Collaboration Suite (ZCS) Cross-site Scripting Vulnerability: CISA added CVE-2025-27915 to the KEV catalog (due 2025-10-28).</p>