CVE-2026-84554 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 attacker in a privileged network position may be able to cause a denial-of-service.
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Analysis
by VulDB Data Team • 09/15/2026
The vulnerability described involves an integer overflow condition within the networking stack 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 is too large for the data type used to store it, causing the value to wrap around or truncate unexpectedly. In this context, the flaw likely stems from insufficient validation of input parameters related to network packet sizes or buffer allocations. When an attacker crafts maliciously sized inputs, the system may allocate memory based on a wrapped-around small integer rather than the intended large size, leading to heap corruption or stack overflow conditions that destabilize the operating environment.
From a technical perspective, this flaw aligns with CWE-190, which defines Integer Overflow or Wraparound as a weakness where arithmetic operations produce an incorrect result due to limitations in data representation. The vulnerability is particularly dangerous because it resides within components accessible via network interfaces. An attacker positioned on the same local area network or capable of intercepting traffic can exploit this flaw by sending specially crafted packets that trigger the overflow during processing. This exploitation path corresponds to MITRE ATT&CK technique T1498, Network Denial of Service, as well as potentially T1059 if the overflow leads to code execution in a privileged context, although the primary reported impact is denial-of-service.
The operational impact of this vulnerability is primarily a denial-of-service condition for affected macOS devices. When triggered, the integer overflow can cause kernel panics, application crashes, or complete system freezes, rendering the device unusable until it is rebooted. For enterprise environments relying on these operating systems for critical infrastructure, such instability can lead to significant downtime and loss of productivity. Since the attack requires a privileged network position, the threat actor must have some level of access to the local network segment, which limits the scope compared to remote exploits over the public internet but remains highly relevant in corporate LANs or unsecured Wi-Fi environments where lateral movement is possible.
Mitigation for this vulnerability involves immediate patching of all affected systems to the specified versions: macOS Golden Gate 27, macOS Sequoia 15.8, and macOS Tahoe 26.7. These updates include improved input validation routines that properly check arithmetic bounds before performing operations on network-derived data. In addition to software updates, organizations should enforce strict network segmentation policies to limit access from untrusted or potentially compromised hosts within the local network perimeter. Implementing intrusion detection systems configured to identify anomalous packet sizes or patterns associated with buffer overflow attempts can provide an additional layer of defense against exploitation while patching efforts are completed across the fleet.