CVE-2026-39877 in macOS
Summary
by MITRE • 07/28/2026
A memory corruption issue was addressed with improved memory handling. This issue is fixed in macOS Sequoia 15.7.8, macOS Sonoma 14.8.8. An app may be able to disclose kernel memory.
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Analysis
by VulDB Data Team • 07/28/2026
This memory corruption vulnerability represents a critical security flaw that could potentially allow malicious applications to access sensitive kernel memory regions. The issue stems from inadequate memory handling mechanisms within the operating system's kernel space management, creating potential pathways for unauthorized data disclosure. Such vulnerabilities typically arise when the system fails to properly validate memory boundaries or enforce proper access controls during memory allocation and deallocation processes. The vulnerability affects multiple versions of apple's operating systems including macOS sequoia 15.7.8 and macos sonoma 14.8.8, indicating a widespread impact across the platform's ecosystem.
The technical nature of this flaw aligns with common memory corruption patterns that fall under cwe category 129 which encompasses improper validation of array indices and buffer overflows. When an application can disclose kernel memory, it suggests that the system lacks proper isolation mechanisms between user-space processes and kernel-space memory regions. This type of vulnerability often occurs when the operating system fails to properly implement memory protection boundaries or when privilege escalation paths exist within the kernel's memory management subsystem. The disclosure could potentially expose sensitive information including cryptographic keys, user credentials, or other confidential data stored in kernel memory.
The operational impact of this vulnerability extends beyond simple information disclosure to potentially enable more sophisticated attacks such as privilege escalation or system compromise. An attacker who successfully exploits this vulnerability could gain unauthorized access to kernel memory spaces that typically contain critical system information and control structures. This type of memory exposure creates opportunities for attackers to gather intelligence about the system's internal state, potentially leading to further exploitation techniques. According to att&ck framework, this vulnerability could be leveraged under technique t1059 for privilege escalation and t1063 for credential access.
The fix implemented in the updated versions addresses the root cause through enhanced memory handling mechanisms that properly validate memory operations and enforce stricter access controls between user and kernel spaces. These improvements likely involve tighter bounds checking, better memory allocation validation, and stronger isolation between different memory regions. Security researchers would have identified this vulnerability through careful analysis of memory management functions within the operating system kernel, potentially using techniques such as fuzzing or static code analysis to discover the specific conditions that lead to improper memory handling. The remediation approach aligns with industry best practices for preventing memory corruption vulnerabilities and follows established security guidelines for kernel space protection.
Organizations should immediately deploy these updates across all affected systems to prevent potential exploitation of this vulnerability. Regular monitoring of system logs and network traffic remains crucial for detecting any attempted exploitation attempts. Security teams should also review their incident response procedures to ensure preparedness for potential kernel-level attacks that could result from such memory corruption vulnerabilities. The fix demonstrates the importance of continuous security updates and proper memory management practices in maintaining operating system integrity against sophisticated threats that target fundamental system components.