CVE-2026-84512 in macOS
Summary
by MITRE • 09/15/2026
A buffer overflow was addressed with improved bounds checking. This issue is fixed in macOS Golden Gate 27, macOS Sequoia 15.8, macOS Tahoe 26.7. Mounting a maliciously crafted disk image may cause unexpected system termination or corrupt kernel memory.
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Analysis
by VulDB Data Team • 09/15/2026
The vulnerability described involves a buffer overflow condition within the macOS operating system's handling of disk images. This type of flaw typically arises when software processes input data without adequately verifying its length against the allocated buffer size, allowing an attacker to write more data than the buffer can hold. In this specific instance, the issue was addressed through improved bounds checking mechanisms designed to ensure that all memory accesses remain within their intended limits. The affected components are present in macOS Golden Gate 27, macOS Sequoia 15.8, and macOS Tahoe 26.7, indicating a systemic weakness across multiple recent releases of the operating system's disk image parsing logic.
From a technical perspective, buffer overflows represent a critical class of memory corruption vulnerabilities. When an application writes data beyond the boundaries of a fixed-size buffer, it can overwrite adjacent memory locations that may contain control data such as return addresses or function pointers. In the context of kernel-level operations involved in mounting disk images, this corruption is particularly severe because the kernel operates with high privileges and manages critical system resources. The lack of strict bounds checking allowed maliciously crafted disk image files to trigger out-of-bounds writes during the parsing process. This exploitation path does not require user interaction beyond the act of mounting or accessing the file, making it a potent vector for remote code execution if combined with other techniques, although in this specific report, the immediate observable effects are more limited.
The operational impact of exploiting this vulnerability includes unexpected system termination and potential corruption of kernel memory. Unexpected system termination manifests as a denial of service condition where the operating system crashes or reboots to protect itself from further damage caused by the corrupted state. This disrupts availability for all users on the affected systems. More critically, corrupting kernel memory can lead to undefined behavior that may be leveraged by an attacker to escalate privileges. By carefully crafting the overflow payload, it might be possible to overwrite critical kernel structures, potentially allowing arbitrary code execution with kernel-level permissions. Such a scenario would grant full control over the system, enabling data exfiltration, persistence mechanisms, and complete compromise of confidentiality, integrity, and availability.
This vulnerability aligns with Common Weakness Enumeration (CWE) identifiers such as CWE-120 Buffer Copy without Checking Size of Input Classic Buffer Overflow and potentially CWE-787 Out-of-bounds Write depending on the specific memory layout exploitation details. In terms of tactical mapping to the MITRE ATT&CK framework, this flaw facilitates initial access or privilege escalation techniques that rely on exploiting software vulnerabilities for execution. The attack vector is classified as local if physical or logical access to mount the disk image is required, but it remains a high-risk issue due to the privileged nature of the affected component.
Mitigation strategies primarily involve applying the provided security updates from Apple which include the improved bounds checking logic. Administrators and users should ensure that macOS Golden Gate 27, macOS Sequoia 15.8, or macOS Tahoe 26.7 is installed on all relevant devices to patch this specific flaw. Beyond software updates, defensive measures such as enabling kernel integrity protection features where available can help mitigate the impact of memory corruption by detecting and preventing unauthorized modifications to critical system data. Additionally, restricting the ability of untrusted users or processes to mount arbitrary disk images reduces the attack surface. Security monitoring tools should be configured to detect anomalies in kernel behavior that might indicate an attempted exploitation of this vulnerability, such as frequent crashes or unexpected privilege changes following disk image operations.