High severity · published Sep 14, 2026
CVE-2026-25687
ZCC race condition in ZPA tunnel handler
8.1
CVSS
0.4%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 32% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CC
Client Connector · Zscaler
4.6 before 4.6.0.486; 4.7 before 4.7.0.350; 4.8 before 4.8.0.267; 4.9 before 4.9.0.412 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-25687
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-25687
help.zscaler.com
https://help.zscaler.com/zscaler-client-connector/client-connector-app-release-summary-2026
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