CVE-2026-28919: Apple macOS Privilege Escalation Flaw

CVE-2026-28919 Overview

CVE-2026-28919 is a local privilege escalation vulnerability affecting multiple versions of Apple macOS. The flaw stems from a consistency issue in state handling that allows a malicious application to gain root privileges on affected systems. Apple addressed the vulnerability through improved state handling logic in macOS Sequoia 15.7.7, macOS Sonoma 14.8.7, and macOS Tahoe 26.5. The weakness is classified under [CWE-269] (Improper Privilege Management).

Critical Impact
A local application can elevate to root privileges, compromising full confidentiality, integrity, and availability of the affected macOS system.

Affected Products

Apple macOS Sequoia (versions prior to 15.7.7)
Apple macOS Sonoma (versions prior to 14.8.7)
Apple macOS Tahoe (versions prior to 26.5)

Discovery Timeline

2026-05-11 - CVE-2026-28919 published to the National Vulnerability Database (NVD)
2026-05-12 - Last updated in NVD database

Technical Details for CVE-2026-28919

Vulnerability Analysis

The vulnerability is a local privilege escalation issue rooted in inconsistent state handling within a macOS component. According to Apple's advisory, an app may be able to gain root privileges by exploiting the inconsistency. The flaw requires local access and user interaction, but no prior privileges are needed to launch the exploit. Successful exploitation grants full root-level control over the operating system, allowing attackers to read sensitive data, modify system files, and disable security controls.

Root Cause

The root cause is a state handling inconsistency within a privileged macOS subsystem. When the affected component transitions between operational states, it fails to enforce uniform privilege checks, opening a window where a low-privileged process can invoke privileged functionality. This class of defect maps to [CWE-269] Improper Privilege Management and frequently appears in components that mediate between user-space requests and kernel or system-level operations.

Attack Vector

Exploitation requires an attacker to deliver and execute a malicious application on the target macOS host. The local attack vector means remote network exploitation is not possible without first achieving code execution on the system. Common delivery paths include trojanized software downloads, malicious installers distributed through phishing campaigns, and supply chain compromise of legitimate macOS applications. Once executed, the malicious app triggers the inconsistent state condition to escalate from a standard user context to root.

Apple has not published low-level technical details of the vulnerable code path. Refer to the Apple Support Document #127115, Apple Support Document #127116, and Apple Support Document #127117 for vendor guidance.

Detection Methods for CVE-2026-28919

Indicators of Compromise

Unexpected processes executing with uid=0 (root) that were spawned by user-level applications
Newly created launchd property list files in /Library/LaunchDaemons/ or /System/Library/LaunchDaemons/ outside of patch windows
Unsigned or ad-hoc signed binaries executing privileged operations such as modifying /etc/sudoers or system keychains
Unauthorized modifications to system integrity-protected paths after process state transitions

Detection Strategies

Monitor for child processes that elevate privileges without an associated sudo, authd, or SecurityAgent prompt event
Establish behavioral baselines for applications and alert on deviations such as a sandboxed app invoking XPC services that yield root processes
Correlate Endpoint Security Framework (ESF) events for ES_EVENT_TYPE_NOTIFY_EXEC with effective UID changes

Monitoring Recommendations

Ingest macOS Unified Logs and ESF telemetry into a centralized SIEM for cross-host correlation
Track installation and execution of newly observed applications, particularly those signed with developer IDs lacking reputation
Audit sudo logs, authd events, and TCC database changes for anomalies that may indicate post-exploitation activity

How to Mitigate CVE-2026-28919

Immediate Actions Required

Update affected systems to macOS Sequoia 15.7.7, macOS Sonoma 14.8.7, or macOS Tahoe 26.5 as soon as operationally feasible
Inventory macOS endpoints across the environment and prioritize patching for hosts with administrative or developer users
Restrict installation of unsigned or untrusted applications through Gatekeeper and managed device policies
Review recent application installations and execution logs for suspicious activity that predates patch deployment

Patch Information

Apple released fixes in macOS Sequoia 15.7.7, macOS Sonoma 14.8.7, and macOS Tahoe 26.5. Patch details are documented in Apple Support Document #127115, Apple Support Document #127116, and Apple Support Document #127117. Administrators should deploy the updates through Software Update, MDM, or Apple's enterprise patching workflows.

Workarounds

Enforce least-privilege user accounts and remove local administrator rights where not strictly required
Use MDM policies to block execution of applications from unidentified developers and restrict downloads to vetted sources
Enable System Integrity Protection (SIP) and ensure FileVault and Gatekeeper remain active on all endpoints

bash

# Verify current macOS version and confirm patch status
sw_vers -productVersion

# Trigger software update check and install available updates
sudo softwareupdate --list
sudo softwareupdate --install --all --restart