CVE-2026-84553 in macOS
Summary
by MITRE • 09/15/2026
A resource exhaustion issue was addressed with improved input validation. This issue is fixed in macOS Golden Gate 27, macOS Sequoia 15.8, macOS Tahoe 26.7. A remote attacker may be able to cause a denial-of-service.
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Analysis
by VulDB Data Team • 09/15/2026
The vulnerability described constitutes a resource exhaustion flaw within the operating system's input processing mechanisms, specifically addressed through enhanced validation protocols in recent updates for macOS Golden Gate 27, macOS Sequoia 15.8, and macOS Tahoe 26.7. This type of issue typically arises when an application or system component fails to properly validate the size, structure, or complexity of incoming data before allocating resources such as memory buffers, file descriptors, or CPU cycles. By neglecting these checks, the software becomes susceptible to scenarios where a remote attacker can supply malformed or excessively large inputs that trigger disproportionate resource consumption relative to the input volume. The core technical flaw lies in the absence of strict boundary checking and rate limiting during the parsing phase, allowing an adversary to force the system into a state of saturation without necessarily exploiting code execution vulnerabilities.
From an operational perspective, this vulnerability enables a remote denial-of-service attack against affected macOS devices. An attacker located on the network can exploit this weakness by sending specially crafted requests or data packets that trigger the resource exhaustion condition. As the system attempts to process these malicious inputs, it consumes excessive amounts of memory or processing power, leading to significant performance degradation or complete unresponsiveness. This impacts the availability component of the CIA triad, preventing legitimate users from accessing services or applications running on the compromised device. In server environments or devices hosting critical infrastructure, such disruptions can lead to substantial downtime and operational losses, while in endpoint scenarios, it may result in a frozen interface requiring a hard reset to restore functionality.
The remediation strategy implemented by Apple involves rigorous input validation techniques designed to detect and reject anomalous data structures before they are processed further down the execution pipeline. This likely includes implementing strict length limits on incoming parameters, validating data types against expected schemas, and potentially introducing timeouts or throttling mechanisms to prevent rapid-fire requests from overwhelming system resources. These measures ensure that only well-formed and reasonably sized inputs are accepted for processing, thereby neutralizing the attack vector used to trigger resource exhaustion. The inclusion of this fix in multiple major macOS releases indicates a coordinated effort across different product lines to address systemic weaknesses in input handling logic.
This vulnerability aligns with Common Weakness Enumeration identifier CWE-400, which describes uncontrolled resource consumption where an actor can cause a system or application to consume excessive resources such as memory, disk space, or CPU time. Furthermore, the exploitation technique maps directly to MITRE ATT&CK tactic T1499, specifically subcategory Endpoint Denial of Service, wherein adversaries aim to disrupt service availability by exhausting computational resources rather than compromising data integrity or confidentiality. Security administrators should ensure that all macOS endpoints are updated to at least the specified versions to mitigate this risk. Additionally, implementing network-level monitoring for unusual spikes in resource usage can help detect potential exploitation attempts in real-time, providing an additional layer of defense beyond the patched software itself.