CVE-2026-24071: Native Access Privilege Escalation Flaw

CVE-2026-24071 Overview

A Time-of-Check Time-of-Use (TOCTOU) race condition vulnerability has been identified in the XPC service offered by the privileged helper of Native Access for macOS. The vulnerability exists because the privileged helper uses the PID (Process ID) of the connecting client to verify its code signature. This is considered insecure and can be exploited by PID reuse attacks. The connection handler function uses _xpc_connection_get_pid(arg2) as an argument for the hasValidSignature function. This value cannot be trusted since it is vulnerable to PID reuse attacks, potentially allowing a malicious process to impersonate a legitimate client and gain elevated privileges.

Critical Impact

Local attackers with low privileges can exploit this race condition to bypass code signature verification, potentially achieving privilege escalation with high impact to confidentiality, integrity, and availability.

Affected Products

• Native Access for macOS (privileged helper XPC service)

Discovery Timeline

• 2026-02-02 - CVE-2026-24071 published to NVD
• 2026-02-03 - Last updated in NVD database

Technical Details for CVE-2026-24071

Vulnerability Analysis

This vulnerability is classified as CWE-367: Time-of-Check Time-of-Use (TOCTOU) Race Condition. The core issue lies in the privileged helper's flawed approach to client verification. When a client connects to the XPC service, the helper retrieves the client's PID using _xpc_connection_get_pid() and passes this value to a signature verification function called hasValidSignature.

The fundamental problem is that PIDs are ephemeral identifiers that the operating system recycles. Between the time the PID is retrieved and when the signature check is performed, an attacker can terminate the legitimate process and spawn a malicious process that reuses the same PID. This classic TOCTOU race condition allows the malicious process to inherit the trust that was validated for a different, legitimate process.

Root Cause

The root cause stems from using process identifiers (PIDs) as a trust anchor for code signature verification in inter-process communication. PIDs are not cryptographically bound to process identity and can be reused by the operating system when processes terminate. The privileged helper should instead use the audit token provided by XPC, which offers a more reliable and race-condition-free method of identifying connecting clients. The audit token contains additional validation data that remains consistent throughout the connection lifecycle.

Attack Vector

This vulnerability requires local access to the system. An attacker with low-level privileges can exploit this by monitoring XPC connections to the privileged helper. When a legitimate, signed application initiates a connection, the attacker rapidly terminates that process and spawns their own malicious process to inherit the recycled PID. Due to the race condition in the verification logic, the attacker's process may successfully authenticate to the privileged helper using the credentials verified against the now-terminated legitimate process. This can result in privilege escalation with cross-scope impact affecting system confidentiality, integrity, and availability.

The attack requires precise timing (high attack complexity) but does not require user interaction, making it feasible for determined attackers with local access.

Detection Methods for CVE-2026-24071

Indicators of Compromise

• Unusual process termination patterns followed by rapid process creation with sequential or nearby PIDs
• Unexpected XPC connections to the Native Access privileged helper from unsigned or untrusted binaries
• Anomalous privilege escalation events associated with the Native Access application

Detection Strategies

• Monitor XPC connection patterns to the Native Access privileged helper for signs of PID manipulation
• Implement process behavior analytics to detect rapid PID cycling and process replacement patterns
• Configure endpoint detection to alert on suspicious privilege escalation chains involving Native Access components

Monitoring Recommendations

• Enable detailed logging for XPC service connections on macOS systems running Native Access
• Deploy behavioral monitoring for privileged helper processes to detect race condition exploitation attempts
• Review system logs for failed signature verification attempts followed by successful connections from the same PID range

How to Mitigate CVE-2026-24071

Immediate Actions Required

• Review and restrict access to systems running vulnerable versions of Native Access
• Limit local user access to systems where the Native Access privileged helper is installed
• Monitor for exploitation attempts using endpoint detection and response solutions

Patch Information

Consult the SEC Consult Advisory for detailed vulnerability information and remediation guidance. Contact Native Instruments for official patch availability and update instructions for affected Native Access installations.

Workarounds

• Consider temporarily disabling or removing the Native Access privileged helper until a patch is available
• Implement strict local access controls to minimize the attack surface for local privilege escalation
• Deploy application whitelisting to prevent unauthorized processes from interacting with XPC services
• Use SentinelOne's behavioral AI to detect and block exploitation attempts targeting this race condition vulnerability