CVE-2026-84517 in macOS
Summary
by MITRE • 09/15/2026
An integer overflow was addressed with improved input validation. 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.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 09/15/2026
The vulnerability described involves an integer overflow condition within the core components of Apple's operating systems, specifically affecting versions prior to macOS Golden Gate 27, macOS Sequoia 15.8, and macOS Tahoe 26.7. Integer overflows occur when a calculation results in a numeric value that exceeds the maximum capacity for storage defined by its data type. In this context, the flaw likely stems from insufficient validation of input values during arithmetic operations or memory allocation processes within system libraries or kernel extensions. When an attacker provides crafted input that triggers such an overflow, the resulting miscalculation can lead to incorrect buffer sizes being allocated or accessed, potentially causing a write-out-of-bounds condition or triggering a critical assertion failure in the operating system's error handling mechanisms.
From a technical perspective, this issue aligns with Common Weakness Enumeration (CWE) category CWE-190: Integer Overflow or Wraparound. The lack of rigorous bounds checking allows malicious actors to manipulate internal state variables in ways that bypass expected logical constraints. While integer overflows are often associated with memory corruption exploits leading to arbitrary code execution, the specific impact noted here is system termination. This suggests that the vulnerability triggers a fatal exception or panic condition rather than allowing for successful exploitation of control flow hijacking. The operating system's safety mechanisms detect the inconsistent state caused by the overflow and initiate an immediate shutdown to prevent further potential damage or data corruption, resulting in a denial of service scenario where the affected application or entire system becomes unresponsive until rebooted.
The operational impact of this vulnerability is primarily centered on availability rather than confidentiality or integrity. An authenticated local user can exploit this flaw by triggering specific actions within an application that interacts with the vulnerable component. By supplying specially crafted data, the attacker can cause unexpected system termination, effectively denying service to legitimate users and disrupting ongoing processes. This type of denial-of-service attack is particularly disruptive in environments requiring high uptime or where continuous operation is critical. Although it does not directly compromise user data or allow privilege escalation, the repeated occurrence of such crashes can lead to significant productivity losses and potential instability if multiple instances are triggered concurrently.
Mitigation for this vulnerability requires immediate patching of all affected systems. Administrators should ensure that macOS Golden Gate 27, macOS Sequoia 15.8, and macOS Tahoe 26.7 or later versions are installed across all endpoints to apply the improved input validation logic developed by Apple engineers. This update addresses the root cause by enforcing stricter checks on numeric inputs before they are processed in critical system routines. In addition to patching, organizations should implement network segmentation and least-privilege access controls to limit the ability of untrusted users or applications to interact with sensitive system components. Monitoring for unusual process termination patterns can also aid in detecting potential exploitation attempts while patches are being deployed.