CVE-2026-59564
CriticalCVSS 9.1Exploitation Probability (EPSS)
Low risk22th percentile - higher than 22% of all known CVEs
Summary
An authentication bypass issue exists in communications between affected versions of the Zscaler Client Connector and the Zscaler Client Connector Portal.
Risk Assessment
The risk includes potential unauthorized access to the portal or manipulation of communication, potentially leading to compromise of client configuration integrity and potential endpoint takeover.
Recommendation
It is recommended to update Zscaler Client Connector to a version that includes a fix for this issue, and to verify the integrity of communication with the portal.
Other vulnerabilities in Zscaler Client Connector
See all- CVE-2026-59568Critical
Multiple vulnerabilities on affected versions of Zscaler Client Connector allow remote code execution, giving an unauthenticated, unprivileged user the ability to execute arbitrary code in the ZCC context.
- CVE-2026-59570High
On affected versions of Zscaler client connector, a pre-installed peer app can tear down the Zscaler tunnel, force user logout, and toggle packet capture.
- CVE-2026-59569High
An improper input validation vulnerability in Zscaler Client Connector on Android and ChromeOS allows an attacker to potentially bypass Zscaler controls.
- CVE-2026-25687High
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.
- CVE-2026-59567High
Multiple vulnerabilities in Zscaler Client Connector allow local privilege escalation, giving an unprivileged user the ability to execute arbitrary code in a privileged context.
- CVE-2026-59566High
A locally exploitable buffer overflow bug can cause a local denial-of-service attack on Zscaler Client Connector on Android and ChromeOS.
- CVE-2026-59565High
A remotely exploitable buffer overflow bug can cause a local and kernel denial-of-service attack on Zscaler Client Connector on Windows.
- CVE-2026-22569Medium
An incorrect startup configuration of Zscaler Client Connector on Windows may cause a limited amount of traffic to bypass inspection under rare circumstances.
Original NVD description (English source)
An authentication bypass issue exists in communications between affected versions of the Zscaler Client Connector and the Zscaler Client Connector Portal.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS