CVE-2026-64767: Apple macOS Buffer Overflow Vulnerability

CVE-2026-64767 Overview

CVE-2026-64767 is a buffer overflow vulnerability in Apple macOS that allows a remote attacker to cause unexpected system termination or corrupt kernel memory. The flaw is classified under [CWE-120] (Buffer Copy without Checking Size of Input) and requires no authentication or user interaction to exploit over the network.

Apple addressed the issue with improved bounds checking in macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, and macOS Tahoe 26.6. Successful exploitation can lead to kernel memory corruption, which can escalate to arbitrary code execution in kernel context.

Critical Impact
Remote attackers can trigger unexpected system termination or corrupt kernel memory without authentication, potentially leading to full system compromise.

Affected Products

Apple macOS Sequoia versions prior to 15.7.8
Apple macOS Sonoma versions prior to 14.8.8
Apple macOS Tahoe versions prior to 26.6

Discovery Timeline

2026-07-27 - CVE-2026-64767 published to NVD
2026-07-28 - Last updated in NVD database

Technical Details for CVE-2026-64767

Vulnerability Analysis

The vulnerability is a classic buffer overflow [CWE-120] within a macOS component that processes network-reachable input. Apple's advisories describe the fix as "improved bounds checking," indicating that the affected code copied attacker-controlled data into a fixed-size buffer without validating input length against the destination capacity.

Because the outcome includes kernel memory corruption, the vulnerable code path executes in or interacts directly with kernel memory. An attacker sending a crafted network payload can overwrite adjacent memory structures, causing a kernel panic (unexpected system termination) or manipulating kernel state.

The EPSS probability is 0.445%, reflecting that no public exploitation has been observed at this time. Apple has not publicly disclosed the specific component to limit exploitation risk during patch rollout.

Root Cause

The root cause is missing or insufficient bounds validation before writing external input into a bounded memory region. When the source data exceeds the destination buffer, adjacent memory is overwritten, corrupting kernel data structures or control flow metadata.

Attack Vector

An attacker exploits this issue remotely by delivering a malformed network packet or protocol message to a vulnerable macOS host. No prior credentials or user interaction are required. See the Apple advisories for the affected component and version-specific fixes: Apple Security Advisory 128067, Apple Security Advisory 128071, and Apple Security Advisory 128072.

No public proof-of-concept code is currently available for CVE-2026-64767.

Detection Methods for CVE-2026-64767

Indicators of Compromise

Unexpected kernel panics or system reboots on macOS hosts, particularly clustered across multiple endpoints on the same network segment.
Anomalous inbound network traffic to macOS systems containing oversized or malformed protocol fields.
Crash reports in /Library/Logs/DiagnosticReports/ referencing kernel extensions or network stack components.

Detection Strategies

Monitor macOS endpoints for repeated kernel panics and correlate with inbound network flows preceding the crash.
Deploy network intrusion detection signatures for oversized packets targeting macOS systems on ports commonly used by Apple services.
Inventory macOS versions across the fleet and flag any host running versions earlier than 15.7.8, 14.8.8, or 26.6.

Monitoring Recommendations

Centralize macOS crash reports and kernel logs for correlation and anomaly analysis.
Track outbound connections from macOS hosts following kernel panics, which may indicate post-exploitation activity.
Alert on unpatched macOS versions during endpoint compliance checks.

How to Mitigate CVE-2026-64767

Immediate Actions Required

Apply Apple's security updates for macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, or macOS Tahoe 26.6 as documented in the vendor advisories.
Prioritize patching of internet-facing and high-value macOS systems, including developer workstations and servers.
Restrict inbound network access to macOS endpoints from untrusted networks until patching is complete.

Patch Information

Apple released patches in macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, and macOS Tahoe 26.6. Full details are available at Apple Security Advisory 128067, Apple Security Advisory 128071, and Apple Security Advisory 128072. The fix implements improved bounds checking on the affected input path.

Workarounds

Segment macOS hosts behind firewalls that filter unsolicited inbound traffic from untrusted networks.
Disable or block network-facing services on macOS that are not required for business operations.
Enforce host-based firewall rules using pfctl to restrict inbound traffic to known sources until the patch is applied.

bash

# Verify installed macOS version and confirm patch level
sw_vers -productVersion

# Trigger a software update check to install the security patch
sudo softwareupdate --install --all --restart