THREAT OPS › CVEs › CVE-2025-66376
CVE-2025-66376 — Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting Vulnerability
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.
Vulnerability details
- Affected productsZimbra Collaboration Suite (ZCS)
- KEV remediation due2026-04-01
Related reporting
- July 2026 CVE Landscaperecordedfuture
- Russian State-Supported Cyber Actors Conduct Phishing Campaign Targeting Users of Zimbra Collaboration Suitecisa_advisories
- 27th July – Threat Intelligence Reportcheckpoint_research