CVE-2026-28841: Apple macOS Buffer Overflow Vulnerability

CVE-2026-28841 Overview

CVE-2026-28841 is a buffer overflow vulnerability affecting Apple macOS that was addressed with improved size validation. This vulnerability allows a local attacker to trigger memory corruption through improper buffer boundary handling, potentially resulting in unexpected application termination and denial of service conditions. The vulnerability is classified as CWE-120 (Buffer Copy without Checking Size of Input).

Critical Impact

A buffer overflow may result in memory corruption and unexpected app termination, leading to denial of service on affected macOS systems.

Affected Products

• Apple macOS (versions prior to macOS Tahoe 26.4)

Discovery Timeline

• 2026-03-25 - CVE-2026-28841 published to NVD
• 2026-03-25 - Last updated in NVD database

Technical Details for CVE-2026-28841

Vulnerability Analysis

This buffer overflow vulnerability stems from insufficient size validation when processing input data in macOS. When exploited, an attacker with local access can craft malicious input that exceeds expected buffer boundaries, causing memory to be overwritten beyond allocated regions. The impact is primarily focused on system availability, as successful exploitation leads to memory corruption and application crashes.

The vulnerability requires local access to exploit, meaning an attacker must have some form of access to the target macOS system. No user interaction is required for exploitation, and no privileges are needed to trigger the vulnerable code path. While the vulnerability does not enable data theft or integrity violations, the availability impact is significant as it can crash applications and potentially destabilize system operation.

Root Cause

The root cause of CVE-2026-28841 is a classic buffer overflow (CWE-120) where data is copied into a buffer without adequate validation of the input size relative to the destination buffer's capacity. Apple addressed this by implementing improved size validation to ensure that input data cannot exceed the allocated buffer boundaries.

Attack Vector

The attack vector for CVE-2026-28841 is local, requiring the attacker to have access to the target macOS system. Exploitation involves providing specially crafted input that triggers the buffer overflow condition. Since no privileges are required and no user interaction is needed, any local user or process could potentially trigger this vulnerability.

The vulnerability mechanism involves inadequate bounds checking during buffer operations. When input data exceeds the expected size, the overflow corrupts adjacent memory regions, leading to unpredictable application behavior and crashes. Apple's fix implements proper size validation to prevent oversized input from being written to the buffer.

Detection Methods for CVE-2026-28841

Indicators of Compromise

• Unexpected application crashes or terminations on macOS systems
• System logs showing memory corruption errors or segmentation faults
• Repeated crash reports related to buffer overflow conditions

Detection Strategies

• Monitor macOS crash reports for patterns indicating memory corruption issues
• Deploy endpoint detection and response (EDR) solutions capable of detecting buffer overflow exploitation attempts
• Implement application allowlisting to restrict execution of potentially malicious local applications

Monitoring Recommendations

• Enable comprehensive logging on macOS systems to capture crash events and error conditions
• Utilize SentinelOne's behavioral AI to detect anomalous memory access patterns
• Review system logs regularly for signs of denial of service conditions affecting applications

How to Mitigate CVE-2026-28841

Immediate Actions Required

• Update to macOS Tahoe 26.4 or later immediately to address the vulnerability
• Restrict local access to macOS systems to authorized users only
• Monitor systems for signs of exploitation while applying patches
• Review system crash logs for any indication of prior exploitation attempts

Patch Information

Apple has released macOS Tahoe 26.4 which includes the security fix for this buffer overflow vulnerability. The patch implements improved size validation to prevent buffer overflow conditions. Organizations should prioritize updating all affected macOS systems to the patched version.

For detailed patch information, refer to the Apple Support Article.

Workarounds

• Limit local access to macOS systems to trusted users and processes
• Implement endpoint protection solutions to detect and block exploitation attempts
• Consider network segmentation to limit exposure of vulnerable systems
• Monitor system logs for anomalous crash patterns while awaiting patch deployment

# Check current macOS version
sw_vers -productVersion

# Verify system is updated to macOS Tahoe 26.4 or later
# Navigate to: Apple Menu > System Settings > General > Software Update