CVE-2026-113939 in macOS
Summary
by MITRE • 10/26/2026
An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in macOS Golden Gate 27.2. Mounting a maliciously crafted disk image may cause unexpected system termination or corrupt kernel memory.
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Analysis
by VulDB Data Team • 10/27/2026
The vulnerability described involves an out-of-bounds write condition within the macOS operating system, specifically affecting components responsible for handling disk images during mounting operations. This type of flaw typically arises when software fails to properly validate input data before writing it to a designated buffer in memory. In this instance, the underlying issue was addressed by implementing improved bounds checking mechanisms, which ensure that any write operation remains within the allocated limits of the target memory region. Without such safeguards, an attacker can exploit the lack of validation to overwrite adjacent memory locations with arbitrary data, leading to severe system instability or potential code execution scenarios depending on the specific context and memory layout at the time of exploitation.
From a technical perspective, this vulnerability aligns closely with CWE-787: Out-of-bounds Write, which is categorized as a critical class of software defects due to its high likelihood of causing denial of service or privilege escalation. The attack vector requires physical access or the ability to mount a maliciously crafted disk image on the target system. This suggests that while remote exploitation over network protocols might not be directly applicable here without additional vectors, local attackers with user-level privileges can trigger the flaw by inserting or mounting specially constructed storage media. The operational impact of this vulnerability is significant, as it can lead to unexpected system termination, commonly known as a kernel panic in macOS environments, thereby disrupting availability for legitimate users. Furthermore, corruption of kernel memory poses a more severe risk, potentially allowing an attacker to gain elevated privileges or execute arbitrary code with the highest level of access on the affected device.
The remediation strategy employed by Apple involves enhancing the validation logic within the disk image mounting subsystems included in macOS Golden Gate version 27.2 and later releases. By enforcing stricter boundary checks during the parsing and processing of disk image structures, the system prevents invalid memory writes from occurring. This fix mitigates both the denial-of-service aspect caused by system crashes and the confidentiality and integrity risks associated with kernel memory corruption. Organizations managing macOS endpoints should ensure that all devices are updated to this version or newer to eliminate exposure to this specific flaw. Additionally, implementing strict policies regarding the mounting of external storage media can provide an additional layer of defense against such attacks in environments where physical access controls might be less stringent.
In terms of threat intelligence and attack frameworks, this vulnerability reflects techniques often associated with local privilege escalation attempts found within the MITRE ATT&CK framework, particularly those involving memory corruption or exploitation of kernel vulnerabilities for persistence or elevation of privileges. While the immediate impact described is system termination and memory corruption, sophisticated adversaries may leverage such flaws to bypass security controls like System Integrity Protection (SIP) if they can achieve arbitrary write primitives in kernel space. Therefore, maintaining up-to-date software patches remains a critical component of endpoint security hygiene. Security teams should monitor for indicators of compromise related to unusual disk image mounting activities or unexpected system reboots that could signal attempted exploitation of this vulnerability before the patch is applied.