CVE-2026-4018

Deferred Deferred - Pending Action

TOCTOU Race Condition in QNX Neutrino TraceEvent System Call

Publication date: 2026-07-14

Last updated on: 2026-07-15

Assigner: BlackBerry

Description

TOCTOU Race Condition in specific trace commands of the TraceEvent() system call could allow an attacker with local access and with the PROCMGR_AID_TRACE ability, to cause information disclosure, data tampering or a crash of the QNX Neutrino kernel.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-07-14

Last Modified

2026-07-15

Generated

2026-08-04

AI Q&A

2026-07-15

EPSS Evaluated

2026-08-02

NVD

CVE-2026-4018

EUVD

EUVD-2026-44321

Affected Vendors & Products

Vendor	Product	Version / Range
blackberry	qnx_neutrino	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-367	The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check.

Attack-Flow Graph

Executive Summary

This vulnerability is a TOCTOU (Time-of-Check to Time-of-Use) race condition in certain trace commands of the TraceEvent() system call in the QNX Neutrino kernel. It allows an attacker with local access and the PROCMGR_AID_TRACE ability to potentially disclose information, tamper with data, or crash the kernel.

Detection Guidance

Detection of this TOCTOU race condition in QNX Neutrino's TraceEvent() system call requires monitoring for unusual trace command behaviors or kernel crashes. Check system logs for trace-related errors or kernel panics. Since this requires PROCMGR_AID_TRACE privileges, inspect processes running with elevated trace permissions. No specific commands are provided in the context.

Impact Analysis

An attacker could exploit this to read sensitive kernel memory, modify data, or cause a system crash. This could lead to unauthorized access, data corruption, or denial of service on systems running QNX Neutrino with the vulnerable trace commands.

Compliance Impact

This vulnerability could lead to unauthorized data access or tampering, violating confidentiality and integrity requirements in GDPR and HIPAA. Organizations using QNX Neutrino may need to assess and mitigate risks to maintain compliance.

Mitigation Strategies

Disable the PROCMGR_AID_TRACE ability for untrusted users to prevent exploitation. Update the QNX Neutrino kernel to the latest patched version as soon as it becomes available.

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