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Back to active CVEs
Critical · CVSS 9.1CVE-2026-59564

Authentication bypass between ZCC and client connector portalCVE-2026-59564

Answer in brief

CVE-2026-59564 records a Critical severity (CVSS 9.1) vulnerability in Authentication bypass between ZCC and client connector portal. The current sources do not mark it as known exploited. The current feed maps Zscaler/Client Connector (generic), Zscaler/Client Connector (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 24, 2026Updated Aug 28, 2026Source checked Oct 8, 2026First seen by HOL Aug 24, 2026Material review Aug 28, 2026
Upstream Advisory

Key facts

Risk
Critical · CVSS 9.1
Exploitation
Not marked as known exploited
Affected software
2 mapped packages or products
Fix availability
Available

Why this deserves its current priority

CVSS is 9.1. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Zscaler/Client Connector (generic), Zscaler/Client Connector (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
PackageAffected rangeFixed version
Zscaler/Client Connectorgeneric>=0 <Windows: 4.6.0.457 4.7.0.317 4.8.0.232 4.9.0.372 || >=0 <MacOS: 4.5.2.312 4.7.0.292 4.8.0.191 || >=0 <iOS: 4.5.1 || >=0 <Android: 4.2 || >=0 <ChromeOS: 4.2 || >=0 <Linux: 3.7.2.64 4.2.1.64Windows: 4.6.0.457, 4.7.0.317, 4.8.0.232, 4.9.0.372, MacOS: 4.5.2.312, 4.7.0.292, 4.8.0.191, iOS: 4.5.1, Android: 4.2, ChromeOS: 4.2, Linux: 3.7.2.64, 4.2.1.64, Windows:, MacOS:, iOS:, Android:, ChromeOS:, Linux:
Zscaler/Client Connectorgeneric*Not reported

Recommended response

  1. 1Check inventory. Check lockfiles and deployed manifests for Zscaler/Client Connector, Zscaler/Client Connector.
  2. 2Review the reported fix. Update Zscaler/Client Connector to Windows: 4.6.0.457, 4.7.0.317, 4.8.0.232, 4.9.0.372 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

  1. Published upstream

    Aug 24, 2026

    Evidence: source:cvelist:source_dates:source-dates:record

  2. Source modified

    Aug 28, 2026

    Evidence: source:cvelist:source_dates:source-dates:record

  3. First seen by HOL

    Aug 24, 2026

Sources and claim methodology

  • Source referencehelp.zscaler.com
Upstream source description

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

Quoted source text, attributed separately from HOL analysis.

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  • WordPress MainWP Child plugin <= 6.2.1 - Deserialization of untrusted data vulnerabilitySame generic ecosystem
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  • Zimbra Collaboration Suite EWS Extension Authorization Bypass via Crafted Composite Folder/Item IdentifierSame generic ecosystem

Record context

Vulnerability class
Missing Auth
EPSS
Not reported
CWE IDs
CWE-304
Source
CVE List V5
Source checked
Oct 8, 2026
References
1 linked source
Open source record