CVE-2025-66376
Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting Vulnerability
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.
Affected software
Vendor: Synacor · Product: Zimbra Collaboration Suite (ZCS)
Weakness types (CWE):
What to do
This vulnerability appears in CISA's Known Exploited Vulnerabilities catalog, meaning it is being exploited in the wild. Prioritize patching affected systems and verify exposure across your estate.
Related vulnerabilities in Synacor
| CVE | Name | EPSS | Exploited |
|---|---|---|---|
| CVE-2019-9670 | Synacor Zimbra Collaboration Suite (ZCS) Improper Restriction of XML External En | 100.0% | Yes |
| CVE-2024-45519 | Synacor Zimbra Collaboration Suite (ZCS) Command Execution Vulnerability | 99.9% | Yes |
| CVE-2022-27925 | Synacor Zimbra Collaboration Suite (ZCS) Arbitrary File Upload Vulnerability | 98.6% | Yes |
| CVE-2022-41352 | Synacor Zimbra Collaboration Suite (ZCS) Arbitrary File Upload Vulnerability | 95.5% | Yes |
| CVE-2022-37042 | Synacor Zimbra Collaboration Suite (ZCS) Authentication Bypass Vulnerability | 88.8% | Yes |
| CVE-2022-27924 | Synacor Zimbra Collaboration Suite (ZCS) Command Injection Vulnerability | 85.4% | Yes |
| CVE-2020-7796 | Synacor Zimbra Collaboration Suite (ZCS) Server-Side Request Forgery Vulnerabili | 84.4% | Yes |
| CVE-2019-9621 | Synacor Zimbra Collaboration Suite (ZCS) Server-Side Request Forgery (SSRF) Vuln | 80.9% | Yes |
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