CVE

CVE-2025-66376

Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting Vulnerability

Synacor · Zimbra Collaboration Suite (ZCS)

Date added (CISA)

2026-03-18

Remediation due

2026-04-01

Known ransomware use

Not indicated

Remediation priority

P2 — past CISA due date

Associated with

Related to

Lazarus Group (TraderTraitor cluster) / APT38 / BlueNoroff · SPECTREcampaignCorrelated cluster2026-09-16
DysphoriacampaignCorrelated cluster2026-08-24

Description

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.

Source: NVD ↗ · CISA KEV Catalog ↗