CVE-2026-28925: Apple macOS Buffer Overflow Vulnerability

CVE-2026-28925 Overview

CVE-2026-28925 is a buffer overflow vulnerability affecting multiple versions of Apple macOS. The flaw allows a local application to trigger unexpected system termination or write to kernel memory. Apple addressed the issue through improved bounds checking in macOS Sequoia 15.7.7, macOS Sonoma 14.8.7, and macOS Tahoe 26.5. The weakness maps to [CWE-120] (Buffer Copy without Checking Size of Input). While the CVSS vector indicates a network attack path, Apple's advisory describes the impact as requiring an app to be present on the system, meaning practical exploitation involves a malicious or compromised application.

Critical Impact

A malicious app can write to kernel memory or cause unexpected system termination on unpatched macOS systems.

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-2026-28925 published to NVD
• 2026-05-12 - Last updated in NVD database

Technical Details for CVE-2026-28925

Vulnerability Analysis

The vulnerability is a classic buffer overflow condition [CWE-120] in a macOS component that processes attacker-controlled input without validating its length against the destination buffer size. When the size of the input data exceeds the allocated buffer, adjacent memory is overwritten. Because the overflow reaches kernel memory regions, an attacker can either crash the system or corrupt kernel data structures. Apple's advisory states the fix involves improved bounds checking, indicating the original code path lacked sufficient size validation before performing a memory copy operation.

Root Cause

The root cause is missing or insufficient bounds checking on input data before a copy operation into a fixed-size buffer. Apple has not disclosed the specific component or function. The remediation adds explicit length validation prior to memory copy operations, preventing writes past the buffer boundary. The EPSS score of 0.041% reflects no observed exploitation activity at this time.

Attack Vector

Exploitation requires a local application running on the target system. The malicious app sends crafted input to the vulnerable kernel-facing interface, triggering the overflow. Successful exploitation enables kernel memory writes, which an attacker can chain with other primitives to achieve privilege escalation or kernel-level code execution. The least disruptive outcome is a kernel panic causing denial of service. No public proof-of-concept code is available, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog.

No verified exploitation code is publicly available for this vulnerability. Refer to the Apple Support Article #127115 for vendor-supplied technical context.

Detection Methods for CVE-2026-28925

Indicators of Compromise

• Unexpected kernel panics or system reboots correlated with launching specific third-party applications
• Crash reports in /Library/Logs/DiagnosticReports/ referencing kernel memory faults or invalid memory access
• Recently installed or executed applications from untrusted sources prior to system instability

Detection Strategies

• Monitor macOS endpoints for repeated kernel panic events and correlate with process execution telemetry
• Inventory installed macOS versions and flag hosts running builds earlier than 15.7.7, 14.8.7, or 26.5
• Review application install logs and Gatekeeper events for unsigned or recently sideloaded applications

Monitoring Recommendations

• Forward macOS unified logs and crash reports to a centralized log platform for correlation across the fleet
• Track patch deployment status using mobile device management (MDM) compliance reporting
• Alert on processes spawning from non-standard locations such as /tmp or user-writable directories that subsequently trigger system instability

How to Mitigate CVE-2026-28925

Immediate Actions Required

• Update affected systems to macOS Sequoia 15.7.7, macOS Sonoma 14.8.7, or macOS Tahoe 26.5 immediately
• Enforce patch deployment through MDM policies and verify compliance across all managed endpoints
• Restrict installation of untrusted applications by enabling Gatekeeper and notarization enforcement

Patch Information

Apple released fixes in macOS Sequoia 15.7.7, macOS Sonoma 14.8.7, and macOS Tahoe 26.5. See the official advisories: Apple Support Article #127115, Apple Support Article #127116, and Apple Support Article #127117. The patches add bounds checking to prevent the overflow condition.

Workarounds

• No vendor-supplied workaround exists; applying the security update is the only complete remediation
• Limit local code execution by enforcing application allowlisting and removing unnecessary third-party software
• Restrict standard user accounts from installing applications until patches are deployed

# Verify current macOS version and check for available updates
sw_vers -productVersion
sudo softwareupdate --list
sudo softwareupdate --install --all --restart