Zimbra Collaboration Suite up to 10.0.17/10.1.12 Classic UI cross site scripting

CVSS Meta Temp Score
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CTI Interest Score
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5.8$0-$5k0.00

Summaryinfo

A vulnerability labeled as problematic has been found in Zimbra Collaboration Suite up to 10.0.17/10.1.12. This issue affects some unknown processing of the component Classic UI. The manipulation results in cross site scripting. This vulnerability is reported as CVE-2025-66376. The attack can be launched remotely. Moreover, an exploit is present. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as problematic has been found in Zimbra Collaboration Suite up to 10.0.17/10.1.12. Affected is an unknown part of the component Classic UI. The manipulation with an unknown input leads to a cross site scripting vulnerability. CWE is classifying the issue as CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. This is going to have an impact on integrity. CVE summarizes:

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.

The advisory is shared for download at wiki.zimbra.com. This vulnerability is traded as CVE-2025-66376 since 11/28/2025. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Successful exploitation requires user interaction by the victim. Technical details are unknown but an exploit is available. The MITRE ATT&CK project declares the attack technique as T1059.007.

It is declared as attacked. This issue was added on 03/18/2026 to the CISA Known Exploited Vulnerabilities Catalog with a due date of 04/01/2026:

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Upgrading to version 10.0.18 or 10.1.13 eliminates this vulnerability.

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

Vendor

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.9
VulDB Meta Temp Score: 5.8

VulDB Base Score: 4.3
VulDB Temp Score: 4.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 6.1
NVD Vector: 🔒

CNA Base Score: 7.2
CNA Vector (MITRE): 🔒

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Cross site scripting
CWE: CWE-79 / CWE-94 / CWE-74
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Attacked

EPSS Score: 🔒
EPSS Percentile: 🔒

KEV Added: 🔒
KEV Due: 🔒
KEV Remediation: 🔒
KEV Ransomware: 🔒
KEV Notice: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Collaboration Suite 10.0.18/10.1.13

Timelineinfo

11/28/2025 CVE reserved
01/05/2026 +38 days Advisory disclosed
01/05/2026 +0 days VulDB entry created
03/18/2026 +72 days VulDB entry last update

Sourcesinfo

Advisory: wiki.zimbra.com
Status: Confirmed

CVE: CVE-2025-66376 (🔒)
GCVE (CVE): GCVE-0-2025-66376
GCVE (VulDB): GCVE-100-339552
scip Labs: https://www.scip.ch/en/?labs.20161013

Entryinfo

Created: 01/05/2026 16:06
Updated: 03/18/2026 22:26
Changes: 01/05/2026 16:06 (65), 03/18/2026 21:11 (13), 03/18/2026 22:26 (11)
Complete: 🔍
Cache ID: 216::103

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