CVE-2026-43750: Apple macOS Buffer Overflow Vulnerability

CVE-2026-43750 Overview

CVE-2026-43750 is a buffer overflow vulnerability in Apple macOS that allows an application to execute arbitrary code outside its sandbox or with elevated privileges. Apple addressed the flaw with improved bounds checking. The issue affects multiple macOS versions and is fixed in macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, and macOS Tahoe 26.6. The weakness is classified under [CWE-120] (Buffer Copy without Checking Size of Input).

Critical Impact
A malicious application can escape the macOS sandbox and execute arbitrary code with elevated privileges, undermining core operating-system isolation guarantees.

Affected Products

Apple macOS Sequoia (prior to 15.7.8)
Apple macOS Sonoma (prior to 14.8.8)
Apple macOS Tahoe (prior to 26.6)

Discovery Timeline

2026-07-27 - CVE-2026-43750 published to NVD
2026-07-29 - Last updated in NVD database

Technical Details for CVE-2026-43750

Vulnerability Analysis

The vulnerability is a classic buffer overflow in a macOS component that fails to validate input size before copying data into a fixed-size buffer. Apple resolved the issue by introducing improved bounds checking on the affected code path. When triggered, the overflow corrupts adjacent memory structures, enabling an attacker-controlled application to alter execution flow. Because the flaw permits sandbox escape, an application constrained by macOS App Sandbox policies can break out and interact with resources it should not reach. Successful exploitation can also grant execution under elevated privileges, extending an attacker's access beyond user-level context. The impact spans confidentiality, integrity, and availability of the host system.

Root Cause

The root cause is missing or insufficient size validation before a buffer copy operation, consistent with [CWE-120]. Input data exceeding the destination buffer's capacity overwrites adjacent memory, including control data. The corrected code enforces explicit bounds checks to prevent overwrites.

Attack Vector

Exploitation requires a malicious or compromised application running on the target macOS host. The application supplies crafted input to the vulnerable component to trigger the overflow. No user interaction beyond executing the malicious app is required, and the attacker gains arbitrary code execution outside the sandbox or with elevated privileges. Refer to the Apple Support Document 128067, Apple Support Document 128071, and Apple Support Document 128072 for component-level details.

Detection Methods for CVE-2026-43750

Indicators of Compromise

Unexpected child processes spawned by sandboxed applications, especially processes running outside the parent app's sandbox container.
Crash reports in ~/Library/Logs/DiagnosticReports/ referencing memory corruption, EXC_BAD_ACCESS, or stack/heap overflow signatures in Apple-supplied frameworks.
Sandbox violation entries in system.log or unified logging (log show) originating from unsigned or unexpected binaries.
Anomalous privilege transitions where an unprivileged app performs actions requiring elevated entitlements.

Detection Strategies

Monitor for process executions that deviate from an application's normal sandbox profile, including access to protected file system locations or IPC endpoints.
Correlate application crash telemetry with subsequent suspicious process activity that may indicate successful exploitation.
Baseline macOS endpoint versions and flag hosts still running pre-15.7.8, pre-14.8.8, or pre-26.6 builds.

Monitoring Recommendations

Ingest macOS Endpoint Security Framework events into a centralized detection pipeline to track process, file, and IPC activity.
Alert on entitlement escalations, unexpected task_for_pid usage, and code-signature violations across managed macOS fleets.
Track patch compliance across the environment and generate alerts for hosts missing the July 2026 macOS updates.

How to Mitigate CVE-2026-43750

Immediate Actions Required

Apply Apple's July 2026 security updates to bring macOS hosts to Sequoia 15.7.8, Sonoma 14.8.8, or Tahoe 26.6.
Prioritize patch deployment on developer workstations, privileged administrator systems, and hosts that run untrusted third-party applications.
Restrict installation of unsigned or unnotarized applications until affected systems are patched.

Patch Information

Apple has released fixes in macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, and macOS Tahoe 26.6. Deployment guidance and component-level notes are published in Apple Support Document 128067, Apple Support Document 128071, and Apple Support Document 128072.

Workarounds

No vendor-supplied workaround exists; patching is the only supported remediation path.
Enforce Gatekeeper and notarization requirements to reduce the likelihood of malicious applications executing locally.
Apply MDM policies that block installation of applications from untrusted developers and restrict administrative privileges on user endpoints.

bash

# Verify installed macOS version and confirm patch level
sw_vers
softwareupdate --list
sudo softwareupdate --install --all --restart