What is CVE-2026-59564?

CVE-2026-59564 is a critical-severity vulnerability in Zscaler Client Connector, classified under Missing Critical Step in Authentication. CVSS score: 9.1/10. Published 2026-08-24.

How severe is CVE-2026-59564?

Critical severity. CVSS v3 base score is 9.1 out of 10.

Vulnerability in Zscaler Client Connector

CVE-2026-59564

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

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.

Affected products

Zscaler Client Connector

Weakness classification (CWE)

CWE-304 — Missing Critical Step in Authentication

References

cve@zscaler.com

Frequently asked questions

What is CVE-2026-59564?: CVE-2026-59564 is a critical-severity vulnerability in Zscaler Client Connector, classified under Missing Critical Step in Authentication. CVSS score: 9.1/10. Published 2026-08-24.
How severe is CVE-2026-59564?: Critical severity. CVSS v3 base score is 9.1 out of 10.