---
id: "CVE-2023-34192"
kind: "vulnerability"
aliases: ["CVE-2023-34192"]
title: "synacor zimbra collaboration suite: Cross Site Scripting vulnerability in Zimbra ZCS v.8.8.15 allows a remote authenticated attacker to execute\u2026"
severity: "critical"
cvss: 9.0
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": [], "affected": "= 8.8.15", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["email", "exploited", "package", "self-hosted", "zimbra"]
not_affected_if: ["managed-hosting"]
published_at: "2023-07-06T16:15:10+00:00"
first_seen_at: "2026-10-23T19:11:51+00:00"
updated_at: "2026-10-23T22:29:05+00:00"
sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2023-34192", "first_seen_at": "2026-10-23T19:11:51+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-34192", "first_seen_at": "2026-10-23T22:29:05+00:00"}]
---

# synacor zimbra collaboration suite: Cross Site Scripting vulnerability in Zimbra ZCS v.8.8.15 allows a remote authenticated attacker to execute…

Zimbra Collaboration Suite has a cross-site scripting flaw in the /h/autoSaveDraft endpoint that lets a logged-in user run script in another user's session. Attackers exploit it in the wild, and the sources say it can lead to arbitrary code execution.

_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 = 8.8.15 fixed ?

## Fix

Apply the mitigations from the vendor (Synacor/Zimbra) as CISA requires; the specific patched version is unknown from these sources.
If mitigations are unavailable, CISA says discontinue use of the product.

## Timeline

- 2026-10-23T19:11:51+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2023-34192
- 2026-10-23T22:29:05+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2023-34192

## From the sources

Synacor Zimbra Collaboration Suite (ZCS) contains a cross-site scripting (XSS) vulnerability that allows a remote authenticated attacker to execute arbitrary code via a crafted script to the /h/autoSaveDraft function.

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.

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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_