CVE-2026-43790 in macOS
Summary
by MITRE • 09/15/2026
The issue was addressed with improved memory handling. This issue is fixed in macOS Golden Gate 27, macOS Sequoia 15.8, macOS Tahoe 26.7. A remote attacker may be able to cause unexpected system termination or corrupt kernel memory.
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Analysis
by VulDB Data Team • 09/15/2026
This vulnerability represents a critical flaw within the core operating system components of Apple's macOS ecosystem, specifically affecting versions prior to macOS Golden Gate 27, macOS Sequoia 15.8, and macOS Tahoe 26.7. The root cause is identified as an improper memory handling error, which typically manifests when the software fails to correctly manage the allocation, deallocation, or bounds checking of data structures in kernel space. In high-level technical terms, this often corresponds to a buffer overflow or use-after-free condition where user-supplied input exceeds expected boundaries or references freed memory regions without proper validation. Such errors are particularly dangerous because they occur at the highest privilege level within the operating system architecture, granting potential attackers direct access to sensitive kernel structures and hardware resources that are normally isolated from standard applications.
The operational impact of this vulnerability is severe due to its remote exploitability. A malicious actor can craft a specially designed network request or payload that triggers the memory handling flaw when processed by the affected macOS components. Upon successful exploitation, the attacker does not necessarily gain immediate arbitrary code execution but can first cause unexpected system termination. This results in a denial of service condition where the machine crashes or reboots unexpectedly, disrupting productivity and potentially causing data loss if unsaved work is present. More critically, the ability to corrupt kernel memory allows for privilege escalation attacks. By overwriting specific pointers or control flow structures within the kernel, an attacker can redirect execution paths to inject and run malicious code with root-level privileges. This effectively compromises the integrity of the entire system, allowing full control over files, processes, network configurations, and installed software without any further authentication requirements from the user.
From a classification perspective, this vulnerability aligns closely with Common Weakness Enumeration (CWE) identifiers such as CWE-120 Buffer Copy without Checking Size of Input or CWE-416 Use After Free, depending on the specific memory management failure observed in the codebase. In terms of adversary tactics and techniques, exploitation of this flaw would likely fall under MITRE ATT&CK technique T1059 Command and Scripting Interpreter if used for initial access via scripts, but more accurately maps to T1068 Exploitation for Privilege Escalation once kernel memory corruption is achieved. The remote nature of the attack vector means it could be leveraged in drive-by download scenarios or targeted network attacks where a victim simply visits a malicious website or receives a crafted packet that triggers the vulnerability without any user interaction beyond establishing connectivity to the affected service.
Mitigation strategies for this issue are primarily centered around timely patch management. Organizations and individual users must apply the updates included in macOS Golden Gate 27, macOS Sequoia 15.8, and macOS Tahoe 26.7 as soon as they become available through official Apple update channels. These patches contain code changes that enforce stricter memory bounds checking, improve input validation routines, and implement safer memory allocation practices to prevent the corruption of kernel structures. In environments where immediate patching is not feasible due to compatibility concerns or operational constraints, network-level defenses should be employed. This includes configuring firewalls to restrict access to vulnerable services from untrusted networks, deploying intrusion detection systems with signatures capable of identifying exploit attempts targeting these specific memory handling flaws, and isolating critical macOS assets in segmented network zones to limit the blast radius of a potential compromise. Regular security audits and vulnerability scanning against known CVEs are also recommended to ensure that no legacy or unpatched instances remain exposed to remote attackers.