---
id: CVE-2026-25687
title: >-
  A race condition in the ZPA tunnel handler of affected versions of Zscaler
  Client Connector (ZCC) allows a heap corruption, resulting in a denial of
  service (client crash) and potentially arbitrary code execution in the context
  of the ZC…
summary: >-
  A race condition in the ZPA tunnel handler of affected versions of Zscaler
  Client Connector (ZCC) allows a heap corruption, resulting in a denial of
  service (client crash) and potentially arbitrary code execution in the context
  of the ZC…
severity: high
cvss: 8.1
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-366
vendor: Zscaler
product: Client Connector
affected:
  - client_connector >= 4.6 < 4.6.0.486
  - client_connector >= 4.7 < 4.7.0.350
  - client_connector >= 4.8 < 4.8.0.267
  - client_connector >= 4.9 < 4.9.0.412
published: '2026-09-14'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T19:08:02.707'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-25687'
references:
  - url: >-
      https://help.zscaler.com/zscaler-client-connector/client-connector-app-release-summary-2026
    label: cve@zscaler.com
tags:
  - nvd
  - cve.org
epss: 0.0038
epssPercentile: 0.29237
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-09-14T15:33:09.117567Z'
ingestedAt: '2026-09-14T15:23:07.423Z'
---

## Overview

A race condition in the ZPA tunnel handler of affected versions of Zscaler Client Connector (ZCC) allows a heap corruption, resulting in a denial of service (client crash) and potentially arbitrary code execution in the context of the ZCC process.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.