CVE-2026-84587 in macOS
Summary
by MITRE • 09/15/2026
A permissions issue was addressed with additional restrictions. This issue is fixed in macOS Golden Gate 27, macOS Sequoia 15.8, macOS Tahoe 26.7. An app may be able to access protected user data.
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Analysis
by VulDB Data Team • 09/15/2026
The vulnerability described involves a failure in the operating system's mandatory access control mechanisms within Apple's macOS ecosystem, specifically affecting versions prior to Golden Gate 27, Sequoia 15.8, and Tahoe 26.7. This issue represents a classic permissions bypass where an application is granted unintended access to protected user data that should remain isolated from unprivileged or even certain privileged contexts depending on the specific sandbox configuration. The root cause lies in insufficient restrictions applied during the enforcement of security policies, allowing software to traverse boundaries it was not authorized to cross. Such flaws typically arise when the system fails to properly validate the context of a request against the application's declared entitlements and sandbox profiles, leading to an elevation of privilege or unauthorized data exposure.
From a technical perspective, this flaw aligns with CWE-269 Improper Privilege Management and CWE-732 Incorrect Permission Assignment for Critical Resource. The operating system relies on strict separation between user space applications and sensitive kernel-level resources or protected directories such as the home directory contents, keychain items, or private application support folders. When these boundaries are breached due to a permissions logic error, an attacker can exploit this by crafting malicious software that leverages legitimate but misconfigured APIs to read files it should not access. This is particularly dangerous because macOS applications often have broad default permissions unless explicitly restricted via sandboxing profiles like those enforced by Gatekeeper and the TCC framework for privacy-sensitive data.
The operational impact of this vulnerability is significant, as it compromises user confidentiality and potentially system integrity. An attacker who gains control over an application with these insufficient restrictions can exfiltrate sensitive personal information including documents, photos, messages, and authentication credentials stored in keychains or browser profiles. This capability facilitates further attacks such as identity theft, financial fraud, or corporate espionage if the affected machine is part of a professional environment. Furthermore, because macOS applications are often distributed through official channels that users trust, this vulnerability undermines the security model's foundation by allowing seemingly benign apps to act maliciously without triggering standard alerts for privacy violations.
Mitigation strategies primarily involve immediate software updates to apply the fixes provided in macOS Golden Gate 27, Sequoia 15.8, and Tahoe 26.7. These patches likely include tightened checks within the kernel's security subsystems or updated sandbox profiles that explicitly deny access to protected resources unless strictly necessary for core functionality. Administrators should ensure automatic updates are enabled to prevent exposure windows. Additionally, users can enhance their defense posture by reviewing application permissions in System Settings under Privacy & Security, revoking unnecessary access rights for applications that do not require them. Employing third-party security tools that monitor file system activity and detect anomalous read operations on protected directories can also provide an additional layer of detection against exploitation attempts before the patch is applied.
This incident reflects broader challenges in maintaining robust isolation between user processes and sensitive data stores, a concern frequently mapped to MITRE ATT&CK techniques such as T1005 Data from Local System which describes adversaries collecting data directly from local sources without network communication. By addressing these permission flaws, Apple reinforces the principle of least privilege essential for modern operating system security. Organizations must remain vigilant about patch management cycles and verify that all endpoints are running versions where these specific access control restrictions have been enforced to prevent unauthorized data retrieval attacks.