CVE-2026-84572 in macOS
Summary
by MITRE • 09/15/2026
An out-of-bounds read was addressed with improved bounds checking. This issue is fixed in macOS Golden Gate 27, macOS Sequoia 15.8, macOS Tahoe 26.7. An app may be able to cause unexpected system termination or read kernel memory.
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Analysis
by VulDB Data Team • 09/15/2026
The vulnerability described constitutes a critical out-of-bounds read flaw within the core operating system components of Apple's macOS ecosystem, specifically affecting versions prior to Golden Gate 27, Sequoia 15.8, and Tahoe 26.7. This type of memory safety error typically arises when software accesses data structures beyond their allocated boundaries due to insufficient validation of input parameters or index values. In the context of kernel-level operations, such as those performed by macOS system services, an out-of-bounds read allows a process to retrieve information from adjacent memory locations that were not intended for access. The root cause is fundamentally linked to inadequate bounds checking during data retrieval operations, where the application fails to verify whether the requested offset or index remains within the valid limits of the target buffer or array. This deficiency aligns with Common Weakness Enumeration (CWE) category CWE-125, which defines out-of-bounds read as a condition where software reads memory past the end, or before the beginning, of the intended buffer.
From an operational perspective, the impact of this vulnerability is severe because it involves kernel memory access. When an application triggers this flaw, it can lead to two primary adverse outcomes: unexpected system termination and unauthorized reading of sensitive kernel data. The potential for system termination stems from the fact that accessing invalid or protected memory addresses often causes a fault exception within the operating system's execution environment. If the vulnerability occurs in a critical subsystem without proper error handling mechanisms, this fault can escalate into a panic condition, resulting in an immediate reboot of the device and loss of unsaved work. This denial-of-service aspect disrupts availability for users relying on stable operation of their macOS devices.
More critically, the ability to read kernel memory poses significant confidentiality risks. Kernel space contains sensitive information including security tokens, cryptographic keys, process identifiers, and other privileged data structures that are isolated from user-space applications by design. By exploiting this out-of-bounds read, a malicious actor can extract these secrets without triggering standard access control mechanisms. This capability effectively bypasses the sandboxing protections typically enforced on third-party applications. The extracted information could be leveraged for further attacks, such as privilege escalation or lateral movement within a networked environment. In terms of threat modeling and adversary behavior, this vulnerability facilitates techniques associated with ATT&CK tactic TA0006, Credential Access, specifically sub-techniques involving memory scraping or direct kernel interaction to harvest sensitive data like Kerberos tickets or NTLM hashes if such structures are accessible in the targeted memory regions.
The resolution implemented by Apple involves enhancing bounds checking logic within the affected components. By rigorously validating indices and offsets before accessing memory buffers, the operating system ensures that read operations remain strictly within allocated boundaries. This fix prevents both the accidental fault conditions leading to crashes and the unauthorized data exfiltration paths. To mitigate this risk in environments where patching may be delayed, administrators should enforce strict application whitelisting policies to prevent untrusted code from executing with elevated privileges or accessing sensitive system resources. Additionally, enabling macOS built-in security features such as System Integrity Protection (SIP) can help restrict the ability of user-space processes to interact directly with kernel memory structures, thereby reducing the attack surface even if a vulnerability like this exists in the underlying OS components. Immediate deployment of the specified updates is essential to close these gaps and maintain the integrity and confidentiality of macOS deployments.