Vulnerability Intelligence Report
Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting Vulnerability
CVE-2025-66376
Zimbra Collaboration (ZCS) 10 before 10.0.18 and 10.1 before 10.1.13 allows Classic UI stored XSS via Cascading Style Sheets (CSS) @import directives in an HTML e-mail message.
CISA KEV
SSVC: Active Exploitation
CVSS Base Score
7.2
HIGH
Exploitability:3.9
Impact Score:2.8
EPSS Probability:12.01%
Executive Threat Verdict
Evaluating...
Evaluating Threat Landscape...
Assessing known weaponization, exploitation telemetry, and federal advisories.
Attack Surface
—
Authentication
—
Weaponization
—
SSVC Action
—
Weaknesses (CWE)
CWE-79 ↗CWE-79 Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting')
Affected Products & Versions
| Vendor | Product | Affected Versions |
|---|---|---|
| Zimbra | Collaboration | 10.0 < 10.0.18 (affected), 10.1 < 10.1.13 (affected) |
References & Technical Advisories
No reference links found.
Threat Intelligence Signals
Identity & Timeline
| Status | PUBLISHED |
| Assigning Authority | MITRE Corporation · N/A · USA |
| Reserved | 2025-11-28T00:00:00 |
| Published | 2026-01-05T00:00:00 |
| Last Updated | 2026-03-19T03:55:17 |
Community Chatter & Buzz