CVE-2026-84514: Apple macOS Privilege Escalation Vulnerability

CVE-2026-84514 Overview

CVE-2026-84514 is a missing authorization vulnerability [CWE-862] in Apple macOS. A local application can bypass file system protections and modify areas that should be restricted by the operating system. Apple addressed the issue by adding entitlement checks in the affected component.

The flaw requires local access and low privileges but no user interaction. Successful exploitation allows an attacker to tamper with protected files, undermining system integrity guarantees enforced by macOS. Apple resolved the issue in macOS Golden Gate 27, macOS Sequoia 15.8, and macOS Tahoe 26.7.

Critical Impact
An unprivileged local app can modify protected parts of the macOS file system, breaking integrity controls that guard system binaries and configuration.

Affected Products

Apple macOS versions prior to Golden Gate 27
Apple macOS versions prior to Sequoia 15.8
Apple macOS versions prior to Tahoe 26.7

Discovery Timeline

2026-09-14 - CVE-2026-84514 published to NVD
2026-09-18 - Last updated in NVD database

Technical Details for CVE-2026-84514

Vulnerability Analysis

CVE-2026-84514 stems from missing authorization checks in a macOS component that mediates access to protected file system regions. The affected code path did not verify that the calling process held the required entitlement before performing sensitive file system operations.

An app running locally with standard user privileges can invoke this path to write, replace, or otherwise modify files that macOS integrity controls are intended to protect. The impact is limited to integrity, with no direct confidentiality or availability effect according to the published CVSS vector.

Apple's fix introduces additional entitlement checks so the operating system enforces caller identity and authorization before granting the operation. This aligns with Apple's broader hardening model, which relies on entitlements and System Integrity Protection (SIP) to gate access to sensitive resources.

Root Cause

The root cause is an authorization gap classified as [CWE-862] Missing Authorization. The vulnerable component performed protected file system operations without validating that the requesting process was entitled to perform them. Any local process could reach the code path and trigger unauthorized modifications.

Attack Vector

Exploitation requires local code execution on the target Mac, such as a malicious or trojanized application. The attacker does not need administrative privileges or user interaction. Once running, the app invokes the unprotected interface and modifies files that would normally be blocked by SIP or entitlement policy. No public proof-of-concept, exploit, or in-the-wild activity has been reported at the time of publication.

Because verified exploit code is not published, no code example is included. Refer to Apple's advisories for component-level detail: Apple Support Document 149035, Apple Support Document 149042, and Apple Support Document 149043.

Detection Methods for CVE-2026-84514

Indicators of Compromise

Unexpected modifications to files under SIP-protected paths such as /System, /usr (excluding /usr/local), or /Library/Apple.
Newly installed or unsigned applications invoking private frameworks or XPC services shortly before protected-file changes.
Anomalous writes to launch daemon or launch agent locations under /Library/LaunchDaemons and /Library/LaunchAgents originating from non-installer processes.

Detection Strategies

Baseline the integrity of macOS system directories and alert on hash changes to files that should be immutable between OS updates.
Correlate process telemetry with file modification events to identify unprivileged processes writing to protected paths.
Hunt for processes that request or use entitlements inconsistent with their code signature or developer identity.

Monitoring Recommendations

Enable Endpoint Security framework (ESF) event collection for ES_EVENT_TYPE_NOTIFY_WRITE, RENAME, and UNLINK on protected paths.
Forward macOS unified log events related to amfid, syspolicyd, and taskgated for entitlement and code-signing anomalies.
Track application installation events and cross-reference against Apple notarization status.

How to Mitigate CVE-2026-84514

Immediate Actions Required

Update all Mac endpoints to macOS Golden Gate 27, macOS Sequoia 15.8, or macOS Tahoe 26.7 as appropriate for the hardware.
Inventory macOS fleet versions and prioritize patching for developer, administrator, and privileged-user systems.
Restrict installation of unsigned or non-notarized applications through Gatekeeper policy and MDM configuration profiles.

Patch Information

Apple released fixes in macOS Golden Gate 27, macOS Sequoia 15.8, and macOS Tahoe 26.7. The fix adds entitlement checks to the affected component. See Apple Support Document 149035, Apple Support Document 149042, and Apple Support Document 149043 for advisory details and download instructions.

Workarounds

No official workaround exists; applying the vendor patch is the only supported remediation.
Limit local execution risk by enforcing application allowlisting and blocking unsigned binaries via MDM.
Ensure System Integrity Protection (SIP) remains enabled on all managed endpoints and audit for systems where it has been disabled.

bash

# Verify macOS version and SIP status on managed endpoints
sw_vers -productVersion
csrutil status

# Trigger managed software update via MDM or locally
sudo softwareupdate --install --all --restart