---
id: "CVE-2025-48700"
kind: "vulnerability"
aliases: ["CVE-2025-48700"]
title: "synacor zimbra collaboration suite: An issue was discovered in Zimbra Collaboration (ZCS) 8.8.15 and 9.0 and 10.0 and 10.1"
severity: "high"
cvss: 6.1
epss: null
exploited: true
status: "open"
category: "package"
products: [{"name": "Synacor Zimbra Collaboration Suite (ZCS)", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "synacor zimbra collaboration suite", "fixed": ["10.0.12"], "affected": ">= 10.0.0, < 10.0.12", "ecosystem": "vendor"}, {"name": "synacor zimbra collaboration suite", "fixed": ["10.1.4"], "affected": ">= 10.1.0, < 10.1.4", "ecosystem": "vendor"}, {"name": "synacor zimbra collaboration suite", "fixed": [], "affected": "= 8.8.15", "ecosystem": "vendor"}, {"name": "synacor zimbra collaboration suite", "fixed": [], "affected": "= 9.0.0", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["email", "exploited", "package", "self-hosted", "zimbra"]
not_affected_if: ["managed-hosting"]
published_at: "2025-06-23T15:15:27+00:00"
first_seen_at: "2026-10-23T19:11:51+00:00"
updated_at: "2026-10-23T23:44:51+00:00"
sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2025-48700", "first_seen_at": "2026-10-23T19:11:51+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-48700", "first_seen_at": "2026-10-23T23:44:51+00:00"}]
---

# synacor zimbra collaboration suite: An issue was discovered in Zimbra Collaboration (ZCS) 8.8.15 and 9.0 and 10.0 and 10.1

Synacor Zimbra Collaboration Suite has a cross-site scripting flaw that lets attackers run JavaScript inside a logged-in user's session. Attackers can use that to reach sensitive information in the mailbox.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:Synacor Zimbra Collaboration Suite (ZCS) affected ? fixed ?
- vendor:synacor zimbra collaboration suite affected >= 10.0.0, < 10.0.12 fixed 10.0.12
- vendor:synacor zimbra collaboration suite affected >= 10.1.0, < 10.1.4 fixed 10.1.4
- vendor:synacor zimbra collaboration suite affected = 8.8.15 fixed ?
- vendor:synacor zimbra collaboration suite affected = 9.0.0 fixed ?

## Fix

Apply the vendor mitigations per CISA guidance (BOD 22-01 applies to cloud services); if mitigations are unavailable, discontinue use of the product. Specific patched versions: unknown

## Timeline

- 2026-10-23T19:11:51+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2025-48700
- 2026-10-23T23:44:51+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2025-48700

## From the sources

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.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_