CVE-2026-64694: Apple macOS Integer Overflow DoS Vulnerability

CVE-2026-64694 Overview

CVE-2026-64694 is an integer overflow vulnerability [CWE-190] affecting multiple versions of Apple macOS. Apple addressed the issue with improved input validation across macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, and macOS Tahoe 26.6. According to Apple's advisory, a malicious app may be able to cause unexpected system termination. The vulnerability carries a network attack vector with no privileges or user interaction required, resulting in high impact to confidentiality, integrity, and availability.

Critical Impact
An integer overflow in macOS input handling allows an attacker to trigger unexpected system termination, disrupting availability on affected Mac endpoints.

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-2026-64694 published to NVD
2026-07-28 - Last updated in NVD database

Technical Details for CVE-2026-64694

Vulnerability Analysis

The flaw is an integer overflow condition [CWE-190] in a macOS component that accepts attacker-influenced input. When crafted values exceed the expected numeric range, arithmetic wraps and produces invalid sizes or offsets. Downstream code then operates on the corrupted values and reaches an inconsistent state, forcing the system to terminate. Apple's advisory states the fix implements improved input validation to reject the malformed values before they reach vulnerable arithmetic paths.

Root Cause

The root cause is missing or insufficient validation of numeric input prior to arithmetic operations. Attacker-controlled values are used in size or index calculations that can overflow the underlying integer type. The resulting truncated or wrapped value bypasses subsequent bounds checks and leads to unexpected termination of a system process.

Attack Vector

Apple describes the attacker as "an app" that may cause unexpected system termination. The CVSS vector further characterizes the flaw as network-reachable with no authentication or user interaction. Exploitation therefore requires delivering the crafted input through a local application or a remotely reachable service that ultimately invokes the vulnerable macOS code path. Successful exploitation results in a denial-of-service condition on the host.

No public proof-of-concept exploit code is available for CVE-2026-64694. The vulnerability is not currently listed in the CISA Known Exploited Vulnerabilities catalog. Refer to the Apple Security Update 128067, Apple Security Update 128071, and Apple Security Update 128072 for the authoritative technical details.

Detection Methods for CVE-2026-64694

Indicators of Compromise

Unexpected system panics, kernel restarts, or unexplained reboots on macOS endpoints running vulnerable builds.
Repeated crash reports referencing the same system component in /Library/Logs/DiagnosticReports/.
Applications repeatedly submitting malformed or oversized inputs to system services immediately before a termination event.

Detection Strategies

Inventory macOS endpoints and flag hosts running versions earlier than macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, or macOS Tahoe 26.6.
Correlate crash telemetry with process execution logs to identify applications triggering repeated system terminations.
Alert on newly installed or unsigned applications interacting with system APIs shortly before crash events.

Monitoring Recommendations

Forward ReportCrash and unified log data to a centralized logging platform for retention and query.
Monitor endpoint management tools for macOS build versions and enforce compliance thresholds.
Track process-to-crash relationships to detect exploitation attempts against system components.

How to Mitigate CVE-2026-64694

Immediate Actions Required

Apply Apple's security updates: macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, or macOS Tahoe 26.6.
Prioritize patching for Macs that process untrusted files or connect to untrusted networks.
Audit installed applications and remove any that are unnecessary or from unverified sources.

Patch Information

Apple has released fixed builds addressing the integer overflow through improved input validation. Refer to Apple Security Update 128067, Apple Security Update 128071, and Apple Security Update 128072 for the specific update packages and installation instructions.

Workarounds

No vendor-supplied workaround exists; installing the security update is the supported remediation.
Restrict installation and execution of untrusted applications using Gatekeeper and application control policies until patching completes.
Limit network exposure of affected endpoints where feasible to reduce the attack surface.

bash

# Verify current macOS build and initiate the software update workflow
sw_vers
softwareupdate --list
sudo softwareupdate --install --all --restart