---
id: CVE-2026-59564
title: >-
  An authentication bypass issue exists in communications between affected
  versions of the Zscaler Client Connector and the Zscaler Client Connector
  Portal.
summary: >-
  An authentication bypass issue exists in communications between affected
  versions of the Zscaler Client Connector and the Zscaler Client Connector
  Portal.
severity: critical
cvss: 9.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'
cwe:
  - CWE-304
published: '2026-08-24'
updated: '2026-10-12'
sourceUpdated: '2026-10-12T15:10:00.207'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-59564'
references:
  - url: >-
      https://help.zscaler.com/zscaler-client-connector/client-connector-app-release-summary-2026
    label: cve@zscaler.com
tags:
  - nvd
epss: 0.00529
epssPercentile: 0.43075
ingestedAt: '2026-10-12T15:55:08.116Z'
---

## Overview

An authentication bypass issue exists in communications between affected versions of the Zscaler Client Connector and the Zscaler Client Connector Portal.

## Remediation

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