CVE-2026-43690 in macOS
Summary
by MITRE • 09/15/2026
A race condition was addressed with improved locking. This issue is fixed in macOS Golden Gate 27, macOS Sequoia 15.8, macOS Tahoe 26.7. A local user may be able to read kernel memory.
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Analysis
by VulDB Data Team • 09/15/2026
The disclosed vulnerability represents a classic race condition within the operating system's core subsystems, specifically involving improper synchronization mechanisms during concurrent access operations. In complex software architectures like modern Unix-like kernels, multiple threads or processes often need to share resources such as data structures, file handles, or memory regions. When these shared resources are accessed without adequate locking primitives, a timing window can emerge where the state of the system changes between the time a process checks a condition and the time it acts on that check. In this specific instance, the lack of robust locking allowed for an exploitable sequence where one entity could manipulate or observe kernel data structures while another was in the middle of modifying them, leading to inconsistent states that can be leveraged by malicious actors.
The technical flaw centers on insufficient synchronization during critical sections of code execution within the macOS kernel. Race conditions are particularly dangerous because they are often non-deterministic and difficult to reproduce consistently, making them challenging for developers to detect through standard testing methodologies. The vulnerability likely involves a scenario where a local user can trigger concurrent operations that bypass expected access controls or memory isolation boundaries. By carefully timing their requests, an attacker can exploit the gap between when permissions are verified and when actions are executed, effectively reading kernel memory that should remain inaccessible to unprivileged users. This type of flaw is frequently categorized under CWE-362, which defines race conditions involving concurrent processes, highlighting the failure to properly coordinate access to shared resources.
The operational impact of this vulnerability is significant due to its potential for privilege escalation and information disclosure. Since the exploit allows a local user to read kernel memory, it bypasses the fundamental security boundary between user space and kernel space. Kernel memory often contains sensitive data such as cryptographic keys, authentication tokens, process identifiers, and pointers to other critical system structures. An attacker who successfully exploits this race condition could extract this information to facilitate further attacks, including full system compromise or lateral movement within a networked environment. This aligns with the ATT&CK technique T1057, which covers Process Discovery, as well as techniques related to credential dumping and memory forensics, where attackers harvest secrets from running processes. The ability to read arbitrary kernel memory also opens the door for more advanced exploits that might aim to modify system behavior or hide malicious activity by altering audit logs or security module states.
Mitigation strategies primarily rely on applying the vendor-provided software updates as soon as they become available. For macOS users, this involves updating to macOS Golden Gate 27, macOS Sequoia 15.8, or macOS Tahoe 26.7, depending on the specific deployment environment and version lineage. These patches include improved locking mechanisms that ensure atomicity in critical code paths, thereby eliminating the timing window required for exploitation. Beyond patching, system administrators should enforce strict access controls to limit local user privileges where possible, reducing the attack surface available to potential exploiters. Additionally, deploying endpoint detection and response solutions can help identify anomalous behavior patterns associated with race condition exploits, such as unusual spikes in kernel memory reads or unexpected process interactions. Regular security audits and code reviews focusing on concurrency issues are also recommended for development teams to prevent similar vulnerabilities from being introduced into the software supply chain in the future.