CVE-2025-43262: Apple macOS Privilege Escalation Vulnerability

CVE-2025-43262 Overview

CVE-2025-43262 is a permissions issue in Apple macOS where USB Restricted Mode may not be applied to accessories connected during boot. USB Restricted Mode is a security control that prevents untrusted USB devices from communicating with the system when the device is locked or has not been recently unlocked. Apple addressed the flaw with additional restrictions in macOS Tahoe 26. The weakness is classified under [CWE-358: Improperly Implemented Security Check for Standard].

Critical Impact
An attacker with physical access can connect a USB accessory during system boot to bypass USB Restricted Mode and interact with the host beyond the intended security policy.

Affected Products

Apple macOS versions prior to macOS Tahoe 26
Systems relying on USB Restricted Mode as an accessory-trust boundary
Endpoints where physical port access is not otherwise restricted

Discovery Timeline

2025-09-15 - CVE-2025-43262 published to the National Vulnerability Database (NVD)
2025-09-15 - Apple publishes security advisory for macOS Tahoe 26
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-43262

Vulnerability Analysis

USB Restricted Mode on macOS is designed to gate accessory access based on device state and user consent. The security check that enforces this policy is not consistently applied to accessories that are already connected when the system boots. As a result, a device attached during the boot sequence can be treated as an implicitly trusted accessory and communicate with the host outside the normal restricted-mode workflow.

Exploitation requires local, physical access to a USB port on the target machine. There is no remote attack surface and no authentication is required beyond the ability to attach hardware during power-on. Successful exploitation grants limited access to confidentiality and integrity but does not directly impact availability.

Apple resolved the issue by tightening the permissions check so that USB Restricted Mode is evaluated for accessories connected during boot, not only for those attached after the system reaches a fully booted state.

Root Cause

The root cause is an incomplete enforcement path in the accessory-authorization logic. The check that determines whether an accessory should be subject to USB Restricted Mode did not cover devices enumerated during the early boot window, leaving a gap between hardware enumeration and policy application.

Attack Vector

An attacker with brief physical access powers on or reboots the target machine while a prepared USB accessory is attached. Because the accessory is present during enumeration, the restricted-mode policy is not applied, allowing the device to interact with the host as a permitted peripheral. This can be used to exercise USB attack surface such as HID injection or data exfiltration paths that USB Restricted Mode is intended to block.

No verified public proof-of-concept code is available. See the Apple Support Article and the Full Disclosure Mailing List Post for vendor and community details.

Detection Methods for CVE-2025-43262

Indicators of Compromise

USB device enumeration events in system.log or unified logging that occur during early boot and reference unexpected vendor or product IDs.
HID or mass-storage devices appearing in IOKit registry snapshots on machines where only known peripherals are authorized.
Unexplained reboots followed by new USB accessory attachment records.

Detection Strategies

Collect macOS endpoint telemetry for USB device attach events and correlate them with boot events to identify accessories enumerated before user login.
Baseline authorized USB vendor and product IDs per host and alert on deviations, particularly on shared or kiosk-style Macs.
Review physical security logs alongside endpoint boot records to identify reboots that coincide with unattended access.

Monitoring Recommendations

Forward macOS endpoint logs, including USB and boot events, to a centralized analytics platform for retention and correlation.
Alert on USB accessories that appear only across a reboot boundary and were not previously observed on the host.
Track fleet-wide macOS version inventory to identify systems still running builds prior to macOS Tahoe 26.

How to Mitigate CVE-2025-43262

Immediate Actions Required

Upgrade affected endpoints to macOS Tahoe 26, which contains the corrected USB Restricted Mode enforcement.
Enforce full-disk encryption with FileVault and require a login password at boot to reduce the value of physical USB access.
Restrict physical access to Mac endpoints in shared or public environments and consider port-blocking hardware for high-risk systems.

Patch Information

Apple fixed CVE-2025-43262 in macOS Tahoe 26 by adding additional restrictions to the accessory permissions check so that USB Restricted Mode is evaluated for devices connected during boot. Refer to the Apple Support Article for the official advisory and update instructions.

Workarounds

Power down Mac endpoints when leaving them unattended in untrusted physical environments rather than leaving them logged out but powered on.
Deploy mobile device management (MDM) policies that limit which USB accessories can be used and require user approval for new peripherals.
Disable or physically block unused USB ports on high-value systems where accessory use is not required.

bash

# Verify the installed macOS version to confirm the patch is applied
sw_vers -productVersion

# Example MDM query: list currently attached USB devices for inventory review
system_profiler SPUSBDataType