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TI-2026-20768 Aliases CVE-2026-25687GHSA-4wwc-hgc4-j27v

ZCC race condition in ZPA tunnel handler

Priority LOW 37CWE-366Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
High
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0038 32nd percentileScored 2026-11-07
Fix Fixed Client Connector (Zscaler): 4.6.0.486, 4.7.0.350, 4.8.0.267 +1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
ZscalerClient Connector4.6 to before 4.6.0.486; 4.7 to before 4.7.0.350; 4.8 to before 4.8.0.267; 4.9 to before 4.9.0.4124.6.0.486, 4.7.0.350, 4.8.0.267, 4.9.0.412Patch availableCNA
  • Client Connector VendorZscaler Affected 4.6 to before 4.6.0.486; 4.7 to before 4.7.0.350; 4.8 to before 4.8.0.267; 4.9 to before 4.9.0.412 Fixed in 4.6.0.486, 4.7.0.350, 4.8.0.267, 4.9.0.412 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:zscaler:client_connector:*:*:*:*:*:*:*:*——Zscaler
  • cpe:2.3:a:zscaler:client_connector:*:*:*:*:*:*:*:* Versions — — ·Zscaler

Remediation

  • Fix · CNA Client Connector (Zscaler) Fixed in 4.6.0.486, 4.7.0.350, 4.8.0.267, 4.9.0.412

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-25687
  2. 2026-10-03 Alias added: GHSA-4wwc-hgc4-j27v

References

Other 1

  • TI-2023-22133 Inappropriate file type control in Zscaler Proxy versions 3.6.1.25 and prior allows local… CVSS 3.1MEDIUM 5.5
  • TI-2026-42530 Remote code execution in Zscaler Client Connector CVSS 3.1CRITICAL 9.1
  • TI-2026-42526 Authentication bypass between ZCC and client connector portal CVSS 3.1CRITICAL 9.1
  • TI-2020-09334 The Zscaler Client Connector for Windows prior to 2.1.2.74 had a stack based buffer… CVSS 3.1CRITICAL 9.8
  • TI-2024-15528 Local Privilege Escalation via lack of input validation CVSS 3.1CRITICAL 9.8
  • TI-2025-34691 SAML 2.0 Public Key Validation Issue CVSS 3.1CRITICAL 9.6
See all 58 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences