CVE-2026-64737: Apple macOS Auth Bypass Vulnerability

CVE-2026-64737 Overview

CVE-2026-64737 is an authorization vulnerability in Apple macOS that allows a malicious application to break out of its sandbox. Apple addressed the flaw through improved state management in macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, and macOS Tahoe 26.6. The weakness is categorized under [CWE-284] Improper Access Control. Successful exploitation requires local access and user interaction, but yields a scope change that impacts resources beyond the compromised sandbox.

Critical Impact
A malicious app running under macOS sandbox restrictions can escape its containment boundary and gain access to system resources and user data outside its entitlements.

Affected Products

Apple macOS Sequoia versions prior to 15.7.8
Apple macOS Sonoma versions prior to 14.8.8
Apple macOS Tahoe versions prior to 26.6

Discovery Timeline

2026-07-27 - CVE-2026-64737 published to the National Vulnerability Database
2026-07-28 - Last updated in NVD database

Technical Details for CVE-2026-64737

Vulnerability Analysis

CVE-2026-64737 is an authorization flaw that permits a sandboxed application to perform actions outside its permitted entitlements. The App Sandbox on macOS enforces least-privilege execution by mediating access to files, network resources, and inter-process communication. This vulnerability breaks that mediation by failing to correctly track authorization state across operations.

Apple describes the fix as "improved state management," indicating the underlying component did not consistently maintain authorization decisions between checks. A sandboxed process could reach a state where privileged operations were permitted without a corresponding grant. The scope change reflected in the CVSS vector confirms the exploited component and the affected component differ, meaning the escape crosses a security boundary.

Root Cause

The root cause is improper access control ([CWE-284]) implemented through inconsistent state management within a macOS system component. Authorization decisions were not durably bound to the entity requesting resources, allowing a sandboxed caller to reach an execution path that treated it as authorized. Apple has not published low-level implementation details in the referenced advisories.

Attack Vector

Exploitation requires a malicious application to run locally on the target Mac and requires user interaction, typically launching or approving the app. Once executing under sandbox restrictions, the app abuses the flawed authorization logic to access resources reserved for higher-privileged components. Because delivery relies on convincing a user to run an unsigned or untrusted app, common vectors include trojanized downloads, malicious installers, and applications sideloaded outside the App Store.

No public proof-of-concept or exploit code is available for CVE-2026-64737. Refer to the Apple Support Document 128067, Apple Support Document 128071, and Apple Support Document 128072 for vendor-provided details.

Detection Methods for CVE-2026-64737

Indicators of Compromise

Sandboxed applications spawning child processes or accessing files outside their declared entitlements in Info.plist.
Unexpected xpc or Mach service connections initiated from apps that should be constrained by the App Sandbox.
Applications reading or writing under ~/Library, /Library, or user document directories without a corresponding user-granted permission prompt.

Detection Strategies

Monitor Endpoint Security framework events (ES_EVENT_TYPE_NOTIFY_EXEC, ES_EVENT_TYPE_NOTIFY_OPEN) for sandboxed binaries accessing paths outside their container.
Baseline expected entitlements per application and alert when runtime behavior diverges from the declared sandbox profile.
Correlate unsigned or ad-hoc signed application launches with subsequent access to sensitive user data locations.

Monitoring Recommendations

Ingest macOS Unified Log entries related to sandboxd and amfid denials and anomalous allow decisions into a centralized SIEM.
Track installation events from non-App Store sources and correlate with post-execution file and network activity.
Alert on privilege-relevant TCC prompts triggered by processes without prior user-initiated launch context.

How to Mitigate CVE-2026-64737

Immediate Actions Required

Update affected systems to macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, or macOS Tahoe 26.6.
Audit installed applications from outside the Mac App Store and remove untrusted or unsigned software.
Enforce Gatekeeper and notarization requirements on managed macOS fleets via MDM policy.

Patch Information

Apple released fixes in macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, and macOS Tahoe 26.6. Patch details are published in Apple Support Document 128067, Apple Support Document 128071, and Apple Support Document 128072. Apply the update using Software Update or your MDM patch workflow.

Workarounds

Restrict application installation to the Mac App Store and notarized developers using Gatekeeper policy.
Deploy MDM configuration profiles that block execution of unsigned binaries and quarantine downloaded applications.
Limit standard user accounts from installing software and require administrator approval for new application launches.

bash

# Verify installed macOS version meets patched baseline
sw_vers -productVersion

# Enforce Gatekeeper (App Store and identified developers)
sudo spctl --master-enable
sudo spctl --global-enable

# List quarantined applications for review
find /Applications -xattr com.apple.quarantine -print