CVE-2026-28825: Apple macOS Privilege Escalation Flaw

CVE-2026-28825 Overview

CVE-2026-28825 is an out-of-bounds write vulnerability affecting multiple versions of Apple macOS. This memory corruption flaw occurs due to insufficient bounds checking, allowing a malicious application to write data outside the allocated memory buffer. An attacker who successfully exploits this vulnerability could modify protected parts of the file system, potentially compromising system integrity.

Critical Impact

A local attacker can leverage a malicious application to exploit this out-of-bounds write vulnerability, enabling modification of protected file system areas and potentially compromising macOS system integrity.

Affected Products

• macOS Sequoia (versions prior to 15.7.5)
• macOS Sonoma (versions prior to 14.8.5)
• macOS Tahoe (versions prior to 26.4)

Discovery Timeline

• 2026-03-25 - CVE-2026-28825 published to NVD
• 2026-03-25 - Last updated in NVD database

Technical Details for CVE-2026-28825

Vulnerability Analysis

This vulnerability is classified as CWE-787 (Out-of-bounds Write), a memory corruption issue that occurs when software writes data past the end, or before the beginning, of the intended buffer. In this case, the vulnerability exists within macOS system components where insufficient bounds checking allows write operations to exceed allocated memory regions.

The attack requires local access and user interaction, meaning an attacker would need to convince a user to execute a malicious application. Once executed, the application can exploit the improper bounds checking to write arbitrary data to protected areas of the file system. This type of vulnerability can lead to denial of service conditions through system instability, and potentially enable persistent compromise of system files.

Apple addressed this issue by implementing improved bounds checking to properly validate write operations and ensure data cannot be written outside designated memory boundaries.

Root Cause

The root cause of CVE-2026-28825 is insufficient bounds checking in macOS memory handling routines. When processing certain operations, the affected components fail to properly validate the size and boundaries of write operations, allowing data to be written to memory locations outside the intended buffer. This lack of proper input validation creates a condition where a crafted application can trigger writes to protected file system areas.

Attack Vector

This vulnerability requires local access to the target macOS system. The attack vector involves:

1. An attacker crafts a malicious application designed to trigger the out-of-bounds write condition
2. The victim must be convinced to download and execute the malicious application (user interaction required)
3. Once executed, the application exploits the insufficient bounds checking to write data beyond allocated memory boundaries
4. The out-of-bounds write enables modification of protected file system components

The vulnerability mechanism involves improper memory boundary validation during write operations. When the vulnerable code processes certain inputs, it fails to verify that the destination buffer has sufficient capacity, allowing data to be written past the allocated boundary. For technical details on the specific vulnerable components, refer to Apple Support Document #126794.

Detection Methods for CVE-2026-28825

Indicators of Compromise

• Unexpected modifications to protected system files or directories
• Applications exhibiting unusual file system access patterns to restricted areas
• System logs indicating memory access violations or kernel panics
• Unauthorized changes to macOS system preferences or configurations

Detection Strategies

• Monitor for applications attempting to write to protected file system locations
• Implement file integrity monitoring on critical macOS system files and directories
• Enable macOS audit logging to track file system modification attempts
• Use endpoint detection and response (EDR) solutions to identify memory corruption exploitation attempts

Monitoring Recommendations

• Configure macOS Unified Logging to capture file system access events
• Deploy SentinelOne agents with behavioral analysis capabilities to detect out-of-bounds write exploitation
• Establish baseline behavior for system file access and alert on anomalies
• Monitor for newly installed or unsigned applications that request elevated file system permissions

How to Mitigate CVE-2026-28825

Immediate Actions Required

• Update macOS Sequoia to version 15.7.5 or later
• Update macOS Sonoma to version 14.8.5 or later
• Update macOS Tahoe to version 26.4 or later
• Restrict application installation to trusted sources (Mac App Store or identified developers)

Patch Information

Apple has released security updates to address CVE-2026-28825 with improved bounds checking. The patches are available through the following resources:

• Apple Support Document #126794 - macOS Sequoia 15.7.5
• Apple Support Document #126795 - macOS Sonoma 14.8.5
• Apple Support Document #126796 - macOS Tahoe 26.4

Apply updates immediately through System Preferences > Software Update or via the Mac App Store.

Workarounds

• Enable Gatekeeper and ensure it is set to allow apps only from the App Store and identified developers
• Do not download or execute applications from untrusted sources
• Enable System Integrity Protection (SIP) if disabled to protect critical system files
• Use application allow-listing to prevent unauthorized applications from executing

# Verify System Integrity Protection (SIP) status
csrutil status

# Check Gatekeeper status
spctl --status

# Enable Gatekeeper if disabled
sudo spctl --master-enable

# Verify macOS version after patching
sw_vers -productVersion