CVE-2026-28900 in macOS
Summary
by MITRE • 07/28/2026
A file quarantine bypass was addressed with additional checks. This issue is fixed in macOS Sequoia 15.7.8, macOS Sonoma 14.8.8. A maliciously crafted ZIP archive may bypass Gatekeeper checks.
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Analysis
by VulDB Data Team • 07/28/2026
This vulnerability represents a critical security flaw in Apple's macOS operating system that undermines the fundamental Gatekeeper protection mechanism designed to prevent unauthorized software execution. The issue manifests through a file quarantine bypass technique that allows maliciously crafted ZIP archives to evade the system's security controls, potentially enabling attackers to execute harmful code without proper user consent or system validation.
The technical implementation of this vulnerability stems from insufficient validation checks within the macOS file handling process when processing compressed archives. Gatekeeper, which operates under the principle of preventing unsigned applications from running, relies on quarantine attributes that are typically applied to files downloaded from the internet or received through untrusted sources. When a ZIP archive is processed, the system should verify that all contained files meet security requirements before allowing execution. However, the flaw allows attackers to craft specific ZIP files that can bypass these checks, effectively circumventing the operating system's built-in protection mechanisms.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it represents a fundamental failure in the application sandboxing and code signing validation processes that form the backbone of macOS security architecture. Attackers could leverage this bypass to deploy malware through seemingly benign compressed files, potentially leading to full system compromise, data exfiltration, or persistence mechanisms within affected systems. This vulnerability particularly affects users who regularly download content from untrusted sources or who interact with email attachments and file transfers that may contain malicious payloads.
The fix implemented in macOS Sequoia 15.7.8 and macOS Sonoma 14.8.8 addresses the root cause through enhanced validation routines that properly enforce quarantine checks for all decompressed files within ZIP archives. These updates implement additional cryptographic verification steps and ensure that the security attributes applied during initial download are maintained throughout the decompression process, preventing attackers from exploiting the gap in the system's validation logic.
This vulnerability aligns with CWE-22 (Improper Limitation of a Pathname to a Restricted Directory) and CWE-78 (Improper Neutralization of Special Elements used in OS Command Injection) categories, reflecting the underlying issues of path traversal and command injection that can occur when file handling processes fail to properly validate input. From an ATT&CK framework perspective, this vulnerability maps to T1059 (Command and Scripting Interpreter) and T1203 (Exploitation for Client Execution) techniques, as it enables attackers to execute malicious code through legitimate system interfaces while bypassing standard security controls.
Organizations should prioritize immediate deployment of the recommended macOS updates to address this vulnerability, particularly in environments where users may be exposed to untrusted file sources or where security compliance requirements mandate protection against such attack vectors. Security teams should also implement additional monitoring for unusual decompression activities and file execution patterns that might indicate exploitation attempts. The fix represents a critical defensive measure that reinforces the integrity of macOS's security architecture by ensuring that all files, regardless of their format or delivery method, undergo proper validation before being allowed to execute within the system environment.