CVE-2022-26758: macOS Monterey Use-After-Free Flaw

CVE-2022-26758 Overview

CVE-2022-26758 is a memory corruption vulnerability in Apple macOS Monterey. A malicious application can cause unexpected changes in memory shared between processes, leading to corruption of state across process boundaries. Apple addressed the issue with improved state management in macOS Monterey 12.4. The flaw is classified under [CWE-362] as a concurrent execution using shared resource with improper synchronization, commonly known as a race condition. Local code execution is required to trigger the vulnerability, and successful exploitation can compromise the confidentiality and integrity of data held in shared memory regions.

Critical Impact

A locally-running malicious application can manipulate memory shared between processes, enabling tampering with sensitive data and potentially escalating influence over privileged processes consuming that memory.

Affected Products

• Apple macOS Monterey versions prior to 12.4
• Components leveraging cross-process shared memory on macOS
• Applications dependent on macOS shared memory primitives for inter-process communication

Discovery Timeline

• 2026-06-10 - CVE-2022-26758 published to NVD
• 2026-06-11 - Last updated in NVD database

Technical Details for CVE-2022-26758

Vulnerability Analysis

The vulnerability is a memory corruption issue rooted in improper state management of memory shared between processes on macOS Monterey. Because memory is shared across process boundaries, one process can observe or modify the contents while another process is reading or writing it. The race condition window allows a malicious application to introduce unexpected changes that the consumer process treats as trusted state. The result is corruption of in-memory data structures and potential downstream control-flow influence in the victim process. Apple resolved the issue by tightening state management around the shared memory region, preventing the inconsistent intermediate states that the original implementation allowed.

Root Cause

The underlying defect is a race condition [CWE-362] in code managing shared memory between processes. The original logic did not adequately serialize or validate state transitions, allowing concurrent access to leave the shared region in an unexpected configuration. A malicious process holding access to the shared mapping can deliberately exploit this window to introduce attacker-controlled values.

Attack Vector

Exploitation requires local access. An attacker must execute or coerce execution of a malicious application on the target macOS system. The application interacts with shared memory regions used by another process and races state updates to introduce unexpected modifications. No user interaction is required beyond running the malicious binary, and only low privileges are needed. The vulnerability does not directly grant code execution, but the resulting corruption can be leveraged to influence consumer process behavior.

No public proof-of-concept code is available. Refer to the Apple Support Article 213257 for the official advisory.

Detection Methods for CVE-2022-26758

Indicators of Compromise

• Unsigned or unnotarized applications launching shortly before crashes or unexpected behavior in privileged macOS processes
• Diagnostic reports in /Library/Logs/DiagnosticReports/ showing memory corruption signatures such as EXC_BAD_ACCESS in processes consuming shared memory
• Unexpected child processes spawned from user-installed applications interacting with system IPC endpoints

Detection Strategies

• Inventory macOS endpoints running versions earlier than 12.4 and flag them for prioritized patching
• Hunt for processes mapping shared memory segments using Mach APIs from non-Apple-signed binaries
• Correlate application launches with subsequent crashes of privileged processes through endpoint telemetry

Monitoring Recommendations

• Forward macOS Unified Logs and crash reports to a centralized logging pipeline for retroactive analysis
• Alert on installation or execution of unsigned binaries from user-writable paths such as ~/Downloads and /tmp
• Track macOS build versions across the fleet and generate alerts when hosts fall behind the 12.4 baseline

How to Mitigate CVE-2022-26758

Immediate Actions Required

• Upgrade affected endpoints to macOS Monterey 12.4 or later as documented in Apple Support Article 213257
• Restrict installation of untrusted applications by enforcing Gatekeeper and notarization requirements
• Audit running processes for unexpected user-level applications interacting with system IPC mechanisms

Patch Information

Apple released the fix in macOS Monterey 12.4. The patch addresses the memory corruption issue with improved state management around shared memory regions. Administrators should consult Apple Support Article 102871 for the broader list of Apple security releases and apply the corresponding update through Software Update or a managed deployment tool such as MDM.

Workarounds

• Limit local user accounts to standard (non-administrator) privileges to reduce the impact of malicious application execution
• Enforce application allowlisting through MDM policies to block unapproved binaries from running
• Disable execution from user-writable directories where feasible using endpoint policy controls