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.
- Vendor
- Synacor
- Product
- Zimbra Collaboration Suite (ZCS)
- Added to KEV
- Mar 18, 2026
- Remediation due
- Apr 1, 2026 (US federal deadline)
- Ransomware use
- Not known
- Weakness
- CWE-79
- EPSS
- 20.2% as of Nov 12
In the news
- No Asia-Pacific article names this CVE yet.
References