CVE-2026-86946 in macOS
Summary
by MITRE • 10/26/2026
A use-after-free issue was addressed with improved memory management. This issue is fixed in macOS Golden Gate 27.2, macOS Sequoia 15.8.2, macOS Tahoe 26.7.2. An app may be able to cause unexpected system termination or corrupt kernel memory.
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Analysis
by VulDB Data Team • 10/27/2026
The vulnerability described constitutes a critical use-after-free error within the macOS operating system core components, specifically addressed in updates for macOS Golden Gate version 27.2, macOS Sequoia version 15.8.2, and macOS Tahoe version 26.7.2. This class of memory management flaw arises when software continues to reference a block of memory after it has been freed or deallocated by the system. In the context of kernel-level operations, such errors are particularly severe because they bypass user-space protections that typically limit the blast radius of application crashes. The root cause lies in improper handling of object lifecycles where pointers to released memory structures are not nullified or validated before subsequent access attempts occur. This oversight allows an attacker who can trigger specific system calls or interactions with affected subsystems to manipulate how the kernel interprets the stale pointer, potentially leading to arbitrary code execution if the freed memory is reallocated and populated with controlled data by a malicious process.
From a technical perspective, this vulnerability aligns closely with Common Weakness Enumeration identifier CWE-416, which defines use-after-free conditions as a category of software errors resulting from improper management of dynamic memory allocation. The operational impact of exploiting such a flaw is significant, ranging from denial-of-service scenarios to full system compromise. As noted in the advisory, an unprivileged application may be able to cause unexpected system termination by triggering a kernel panic through invalid memory access patterns. More critically, if the attacker can control the contents of the reallocated memory region before it is accessed via the dangling pointer, they could achieve arbitrary read or write primitives within the kernel space. This capability effectively neutralizes most modern operating system security boundaries, including Kernel Address Space Layout Randomization and Data Execution Prevention, allowing for privilege escalation to root level access.
The exploitation vector typically involves crafting a sequence of memory allocations and deallocations that synchronize with the vulnerable code path in the macOS kernel. By carefully timing these operations, an attacker can ensure that their malicious data occupies the same physical or virtual address previously held by the freed object. When the kernel subsequently dereferences this pointer without checking its validity, it executes instructions or accesses data defined by the attacker. This mechanism is frequently associated with ATT&CK technique T1055, specifically sub-techniques related to process injection and privilege escalation via memory manipulation. The ability to corrupt kernel memory not only destabilizes the host system but also provides a persistent foothold for further lateral movement within networked environments if the compromised machine serves as an entry point.
Mitigation strategies primarily rely on timely patching, as Apple has released specific updates that implement improved memory management practices to prevent these dangling pointer dereferences. Administrators and users should ensure their systems are updated to macOS Golden Gate 27.2, Sequoia 15.8.2, or Tahoe 26.7.2 immediately upon availability. Beyond patching, defense-in-depth measures such as enabling System Integrity Protection can help restrict the ability of user-space applications to interact with sensitive kernel memory regions, thereby raising the bar for successful exploitation even if a vulnerability exists. Additionally, monitoring system logs for unusual kernel panics or unexpected process terminations may provide early indicators of attempted exploitation activities in environments where patching cannot be applied instantly.