CVE-2025-66376

Severity CVSS v4.0:

Pending analysis

Type:

CWE-79 Cross-Site Scripting (XSS)

Publication date:

05/01/2026

Last modified:

18/03/2026

Description

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.

Impact

Vector 3.x

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N CVSS v3.1 Severity and Metrics:

Base Score: 7.20 HIGH
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Changed
Confidentiality (C): Low
Integrity (I): Low
Availability (A): None

Base Score 3.x

7.20

Severity 3.x

HIGH

Vulnerable products and versions

CPE	From	Up to
cpe:2.3:a:synacor:zimbra_collaboration_suite::::::::	10.0.0 (including)	10.0.18 (excluding)
cpe:2.3:a:synacor:zimbra_collaboration_suite::::::::	10.1.0 (including)	10.1.13 (excluding)

To consult the complete list of CPE names with products and versions, see this page

CVE-2025-66376

Description

Impact

Vulnerable products and versions

References to Advisories, Solutions, and Tools