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.
Published: 2026-09-14
Score: 8.1 High
EPSS: < 1% Very Low
KEV: No
Impact: Arbitrary code execution in the Zscaler Client Connector process
Action: Patch Now
AI Analysis

Impact

A race condition in the ZPA tunnel handler of Zscaler Client Connector can corrupt heap memory, causing client crashes and potentially enabling arbitrary code execution within the ZCC process. The flaw is a classic use‑after‑free or double‑free scenario under concurrent tunnel activity and is identified as CWE‑366.

Affected Systems

The vulnerability affects the Zscaler Client Connector product. No specific version ranges are listed in the advisory, so all editions of the connector that include the ZPA tunnel feature are potentially impacted until a patch is applied.

Risk and Exploitability

The CVSS score of 8.1 reflects a high impact, and the EPSS score of < 1% indicates a very low exploitation probability. The issue is not cataloged in CISA KEV, suggesting it is not a known, actively exploited vulnerability at this time. Based on the description, the likely attack vector requires an attacker to manipulate tunnel traffic or perform concurrent client operations to trigger the race, making remote exploitation plausible but potentially dependent on network configurations that allow such traffic.

Generated by OpenCVE AI on September 21, 2026 at 00:13 UTC.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Upgrade Zscaler Client Connector to the latest available version as per vendor release notes.
  • If an immediate upgrade is not feasible, temporarily disable the ZPA tunnel functionality until the fix is applied.
  • Continuously monitor ZCC logs for abnormal crash patterns or memory corruption indicators and reapply the patch promptly if anomalies are detected.

Generated by OpenCVE AI on September 21, 2026 at 00:13 UTC.

Tracking

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Advisories

No advisories yet.

History

Tue, 15 Sep 2026 04:45:00 +0000

Type Values Removed Values Added
First Time appeared Zscaler
Zscaler client Connector
Vendors & Products Zscaler
Zscaler client Connector

Mon, 14 Sep 2026 21:00:00 +0000

Type Values Removed Values Added
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.
Title ZCC race condition in ZPA tunnel handler
Weaknesses CWE-366
References
Metrics cvssV3_1

{'score': 8.1, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Subscriptions

Zscaler Client Connector
cve-icon MITRE

Status: PUBLISHED

Assigner: Zscaler

Published:

Updated: 2026-09-15T03:56:03.896Z

Reserved: 2026-02-05T05:00:40.582Z

Link: CVE-2026-25687

cve-icon Vulnrichment

Updated: 2026-09-14T15:39:38.835Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-09-14T15:17:05.090

Modified: 2026-09-18T19:08:02.707

Link: CVE-2026-25687

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-21T00:15:06Z

Weaknesses
  • CWE-366

    Race Condition within a Thread