CVE-2026-86984 in macOS
Summary
by MITRE • 10/26/2026
A file access issue existed with certain home folder files. This was addressed with improved access restrictions. This issue is fixed in macOS Golden Gate 27.2, macOS Sequoia 15.8.2, macOS Tahoe 26.7.2. An app may be able to access information about a user's contacts.
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Analysis
by VulDB Data Team • 10/27/2026
The vulnerability described involves an improper implementation of file system access controls within the operating system environment, specifically affecting certain home folder files that contain sensitive user data such as contact lists. This issue stems from a flaw in how the operating system enforces sandboxing and permission boundaries for applications requesting access to personal information. Under normal security protocols, applications should be restricted from reading arbitrary files or directories unless explicitly granted permissions through established authorization frameworks. However, due to this oversight, an application could bypass standard checks and retrieve data that is intended to remain private and isolated within the user's home directory structure. This represents a classic case of insufficient access control where the system fails to properly validate whether the requesting process has legitimate authority to view specific resources.
From a technical perspective, this flaw aligns with CWE-284 Improper Access Control, as it allows an unauthorized actor or application to read data that is protected by default security policies. The operational impact of such a vulnerability is significant because contact information often includes personally identifiable information (PII) such as names, phone numbers, email addresses, and sometimes even physical addresses or social connections. If malicious software exploits this weakness, it could exfiltrate these details to remote servers without the user's knowledge or consent. This compromises the confidentiality of the user's data and can lead to further privacy violations, including targeted phishing attacks, identity theft, or unauthorized profiling based on communication patterns. The ability to access contacts also facilitates social engineering campaigns by providing attackers with a trusted list of names that can be used to make malicious communications appear more credible.
This type of vulnerability is often associated with ATT&CK technique T1005 Data from Local System, which describes the collection of data stored locally on an affected system for later exfiltration. By accessing home folder files containing contact information, attackers gain a foothold in gathering intelligence that can be leveraged for subsequent stages of an attack chain. The fix implemented in macOS Golden Gate 27.2, macOS Sequoia 15.8.2, and macOS Tahoe 26.7.2 addresses this by tightening the access restrictions applied to these specific files. This likely involves reinforcing the entitlements required for applications to read contact data, ensuring that only processes with explicit user-granted permissions can interact with sensitive home directory contents related to contacts.
To mitigate such risks in broader contexts, system administrators and users should ensure that all operating systems are updated to the latest patched versions where these access control fixes have been deployed. Additionally, adhering to the principle of least privilege is critical; applications should only be granted permissions necessary for their core functionality. Users can further protect themselves by regularly reviewing app permissions within the operating system's privacy settings and revoking access for any application that does not require contact information to function properly. Regular security audits and monitoring for unusual data access patterns can also help detect potential exploitation attempts early, reducing the window of opportunity for attackers to harvest sensitive user data from local file systems.