CVE-2021-26736: ZApp Installer Privilege Escalation Vulnerabilities

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2023-10-23 · updated 2026-06-17
Weakness: CWE-20

Description

Multiple vulnerabilities in the Zscaler Client Connector Installer and Uninstaller for Windows prior to 3.6 allowed execution of binaries from a low privileged path. A local adversary may be able to execute code with SYSTEM privileges.

Affected products

Zscaler Client Connector: before 3.6 — fixed in 3.6

How to fix

Upgrade to a fixed version: Zscaler Client Connector 3.6. Check the vendor advisory for mitigations.

References

https://help.zscaler.com/zscaler-client-connector/client-connector-app-release-summary-2021
https://help.zscaler.com/zscaler-client-connector/client-connector-app-release-summary-2021

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