CVE-2026-84548 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. Processing a maliciously crafted document may lead to an out-of-bounds read.
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Analysis
by VulDB Data Team • 09/15/2026
The vulnerability described involves an integer overflow within the processing logic of documents on Apple operating systems, specifically affecting versions prior to macOS Golden Gate 27, macOS Sequoia 15.8, and macOS Tahoe 26.7. An integer overflow occurs when a calculation results in a numeric value that exceeds the maximum capacity for storage allocated by the system or application. In this context, the flaw likely stems from insufficient validation of input data sizes during document parsing. When an attacker crafts a malicious document with specific parameters designed to trigger arithmetic errors, such as specifying dimensions or buffer lengths that exceed expected limits, the resulting miscalculation can lead to incorrect memory allocation decisions. This technical failure is categorized under CWE-190, which defines integer overflow or wraparound, and often serves as a precursor to more severe exploitation vectors like out-of-bounds reads if not properly mitigated by subsequent bounds checking mechanisms that fail due to the corrupted state caused by the initial arithmetic error.
The operational impact of this vulnerability is significant because it allows for an out-of-bounds read when processing maliciously crafted documents. An out-of-bounds read, classified under CWE-125, enables an attacker to access memory regions outside the intended buffer boundaries. While typically considered less severe than a write operation in terms of direct code execution potential, reading arbitrary memory can lead to information disclosure vulnerabilities where sensitive data stored adjacent to the target buffer is leaked back to the user or application context. This could potentially expose cryptographic keys, session tokens, or other private information residing in the process memory space. Furthermore, depending on how the read value is subsequently used within the application logic, it may facilitate further exploitation chains that compromise system integrity or availability. The ability to trigger this condition through document processing highlights a risk for users who routinely open files from untrusted sources, such as email attachments or downloaded content.
Mitigation strategies primarily involve updating the operating system to the specified patched versions where improved input validation has been implemented. These updates ensure that numeric inputs are rigorously checked against expected bounds before being used in memory allocation or processing routines, thereby preventing the integer overflow condition from occurring in the first place. In addition to applying software patches, users should adhere to security best practices such as disabling automatic document previewing for untrusted files and utilizing sandboxed environments when opening documents of unknown origin. From a defensive monitoring perspective, this vulnerability aligns with ATT&CK technique T1046, Network Service Discovery, if the read data is exfiltrated over a network, or more accurately T1005, Data from Local System, for local information gathering. Security teams should prioritize patching endpoints running affected macOS versions and monitor for anomalous memory access patterns that might indicate exploitation attempts in environments where immediate patching is not feasible.