External risk intelligence

Directory Path Parsing Flaw Allows Sandbox Breakout

CVE advisorySeverity: CRITICAL (CVSS 9.3)

CVE-2026-64740

This vulnerability affects local applications running on consumer operating systems (iOS, iPadOS, macOS, tvOS). Exploitation requires a malicious app to be already installed and running on the local device to attempt a sandbox breakout, which is not a network-reachable or internet-facing service.

Halo Surface Signal: 1 out of 5 — much less likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A parsing issue in directory path handling has been fixed in recent operating system updates. This vulnerability could allow a malicious application to escape its designated sandbox environment, potentially impacting the confidentiality, integrity, and availability of data. The primary concern is to confirm whether affected systems are running unpatched software and are exposed.

  • Malicious apps could break out of their sandbox.
  • Confirms relevance and exposure on affected systems.
  • Prioritize confirming software versions and exposure.

Attack Path

How an attacker could exploit the issue

Attackers could exploit a flaw in how directory paths are processed, potentially allowing a malicious application to escape its sandbox. This could lead to unauthorized access to sensitive data or further compromise of the system.

  • Entry condition: Malicious app installed on device.
  • Trigger point: Parsing of directory paths.
  • Resulting risk: Sandbox escape and data access.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability could allow a malicious app to escape its sandbox when interacting with directory paths, potentially affecting the app's access to other system resources or data it shouldn't reach.

  • Malicious app sandbox escape.
  • Path validation bypass.
  • Unspecified system data access.

Operational Fix

Recommended remediation, mitigation, and detection steps

This vulnerability impacts Apple operating systems, making device owners and potentially application developers responsible for remediation. The initial focus should be on identifying affected devices, confirming their exposure, and understanding the business criticality of any applications running on them to prioritize actions.

  • Confirm device and application ownership.
  • Verify system reachability and criticality.
  • Plan remediation based on identified risk.

Supplementary metadata

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

Frequently asked questions

What is the software affected by CVE-2026-64740?

This vulnerability affects core Apple operating systems, specifically iOS, iPadOS, macOS (Sequoia, Sonoma, and Tahoe), and tvOS. These platforms use sandboxing as a security foundation to isolate applications from the rest of the system, ensuring that apps cannot access data or resources they are not explicitly authorized to use.

How does the directory path parsing weakness work?

CVE-2026-64740 is categorized as CWE-22, known as Improper Limitation of a Pathname to a Restricted Directory. In plain terms, the software fails to properly validate directory paths, allowing an attacker to manipulate file system requests. This flaw effectively tricks the system into ignoring sandbox boundaries, granting an application access to files or folders it should normally be blocked from reaching.

Can any app trigger this sandbox breakout?

Not inherently. The vulnerability requires a malicious application to be already present and executing on the device. Simply browsing the web or receiving a file does not automatically trigger the bug; the system must process a specifically crafted directory path provided by that installed malicious software to exploit the parsing error.

Do I need to worry if my device is not internet-facing?

According to Halo Surface Signal, this vulnerability is not triggered by network-reachable or internet-facing services. Because exploitation requires local execution of a malicious application, the primary risk is localized to the device itself rather than its exposure to the public internet.

When should I update to resolve this issue?

You should apply the latest OS updates (version 26.6 for iOS, iPadOS, and tvOS; specific versions for macOS) as soon as they are available. The first step is to verify your current system version in your device settings. Updating is the only way to patch the underlying path validation logic and restore the integrity of the sandbox environment.

References