CVE-2026-25687Hinoki check available

Client crash and code execution via tunnel race

Published Sep 14, 2026 · Updated Sep 14, 2026

Heap corruption in the ZPA tunnel handler in Zscaler Client Connector allows attackers to crash the client via a race condition. The handler permits concurrent tunnel operations to race over heap-managed state, corrupting memory used by the ZCC process. Arbitrary code execution in that process is also possible, while attacker access requirements remain undisclosed.

CVSS severityUnavailable
Unscored
EPSS probability0.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Heap corruption in the ZPA tunnel handler in Zscaler Client Connector allows attackers to crash the client via a race condition. The handler permits concurrent tunnel operations to race over heap-managed state, corrupting memory used by the ZCC process. Arbitrary code execution in that process is also possible, while attacker access requirements remain undisclosed.

The record

CVE
CVE-2026-25687
Published
Sep 14, 2026
Updated
Sep 14, 2026
Vendor
Zscaler
Product
Zscaler Client Connector
Classifications
Unavailable
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Sep 14, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 14, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.6 <4.6.0.486
  2. Affected versionversion=4.7 <4.7.0.350
  3. Affected versionversion=4.8 <4.8.0.267
  4. Affected versionversion=4.9 <4.9.0.412

What conditions does exploitation require?

Attack vectorUnavailable in this record.
Required privilegesUnavailable in this record.

What is affected?

Zscaler · Zscaler Client Connectorversion=4.6 <4.6.0.486; version=4.7 <4.7.0.350; version=4.8 <4.8.0.267; version=4.9 <4.9.0.412

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
VectorUnavailable
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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