Zimbra - Cross-Site Scripting via ICS Files

Detects Zimbra Collaboration Suite versions vulnerable to CVE-2025-27915, a stored XSS vulnerability in the Classic Web Client due to insufficient sanitization of HTML content in ICS files. When a user views an email with a malicious ICS entry, embedded JavaScript executes via an ontoggle event...

About Cross Site Scripting – Zimbra Collaboration (CVE-2025-27915) vulnerability

About Cross Site Scripting - Zimbra Collaboration CVE-2025-27915 vulnerability. Zimbra Collaboration is a collaboration software suite, somewhat similar to Microsoft Exchange. Exploiting this vulnerability in the web mail client Classic Web Client allows an unauthenticated attacker to execute...

Zimbra Zero-Day Exploited to Target Brazilian Military via Malicious ICS Files

A now patched security vulnerability in Zimbra Collaboration was exploited as a zero-day earlier this year in cyber attacks targeting the Brazilian military. Tracked as CVE-2025-27915 CVSS score: 5.4, the vulnerability is a stored cross-site scripting XSS vulnerability in the Classic Web Client...

CVE-2025-27915

The CVE-2025-27915 issue affects Zimbra Collaboration (ZCS) Classic Web Client, where insufficient sanitization of HTML in ICS files enables stored XSS when viewing an email with a crafted ICS entry. The underlying flaw allows embedded JavaScript to execute via an ontoggle event inside a tag, en...