CVE-2025-48700

MediumActively exploited (CISA KEV)

Description

An issue was discovered in Zimbra Collaboration (ZCS) 8.8.15 and 9.0 and 10.0 and 10.1. A Cross-Site Scripting (XSS) vulnerability in the Zimbra Classic UI allows attackers to execute arbitrary JavaScript within the user's session, potentially leading to unauthorized access to sensitive information. This issue arises from insufficient sanitization of HTML content, specifically involving crafted tag structures and attribute values that include an @import directive and other script injection vectors. The vulnerability is triggered when a user views a crafted e-mail message in the Classic UI, requiring no additional user interaction.

SeverityMedium
CVSS6.1
Exploit probability—
ProductSynacor Zimbra Collaboration Suite (ZCS)
PublishedJun 23, 2025
First seenJun 23, 2025
Added to KEVApr 20, 2026

How to fix

CISA required action

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

CISA due date: Apr 23, 2026
Update
  • synacor zimbra_collaboration_suite10.0.12, 10.1.4 or later

Affected products

ProductAffected versionsFixed in
synacor zimbra_collaboration_suite10.0.0 ≤ v < 10.0.12, 10.1.0 ≤ v < 10.1.4, 8.8.15, 9.0.010.0.12, 10.1.4

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