VulnerabilitiesCritical
CVE-2025-66376: Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting Vulnerability
Friday, March 20, 2026
Global
CISA KEV - https://www.cisa.gov/known-exploited-vulnerabilities-catalog
Summary
Synacor Zimbra Collaboration Suite (ZCS) contains a cross-site scripting vulnerability in the Classic UI where attackers could abuse Cascading Style Sheets (CSS) @import directives in email HTML.
Threat Analysis
Synacor Zimbra Collaboration Suite (ZCS) contains a cross-site scripting vulnerability in the Classic UI where attackers could abuse Cascading Style Sheets (CSS) @import directives in email HTML. - 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.. Vendor: Synacor. Product: Zimbra Collaboration Suite (ZCS).
Last updated: Mar 20, 2026, 09:19 AM