CVE-2026-84596 in iPadOS
Summary
by MITRE • 09/15/2026
An out-of-bounds read was addressed with improved bounds checking. This issue is fixed in iOS 27 and iPadOS 27, macOS Golden Gate 27, tvOS 27, visionOS 27, watchOS 27. Processing a maliciously crafted font may result in the disclosure of process memory.
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Analysis
by VulDB Data Team • 09/15/2026
The vulnerability described constitutes an out-of-bounds read condition within the system's font processing subsystem, specifically affecting how data is accessed during the parsing and rendering of typeface files. This class of error typically arises when a software component fails to verify that a requested memory access falls within the allocated boundaries of a buffer or array before executing the operation. In this specific instance, the flaw was addressed by implementing improved bounds checking mechanisms, which ensure that any index or offset calculated during font processing is validated against the actual size of the target data structure prior to reading from it. Without such safeguards, an attacker can manipulate input parameters to force the application to read memory locations beyond the intended scope, leading to unauthorized access to sensitive information stored in adjacent memory regions.
The operational impact of this vulnerability centers on the potential disclosure of process memory contents. When a maliciously crafted font file is processed by the operating system or associated applications, the out-of-bounds read allows an attacker to extract arbitrary data from the application's address space. This can include sensitive information such as cryptographic keys, session tokens, user credentials, or other proprietary data that resides in memory alongside the vulnerable buffer. The severity of this impact is heightened because font processing often occurs within privileged system services or applications with broad access rights, meaning the disclosed memory could contain high-value targets rather than just application-specific state. This capability effectively transforms a simple parsing error into a significant information disclosure vector, compromising the confidentiality guarantees expected by users and enterprises relying on these platforms for secure data handling.
From a technical classification perspective, this vulnerability aligns with CWE-125, which defines out-of-bounds read errors where software reads memory outside of intended boundaries. The exploitation scenario described fits squarely within the MITRE ATT&CK framework under Tactic TA0006: Credential Access and Technique T1005, specifically Data from Local System, as it involves extracting data directly from local process memory without requiring remote code execution or privilege escalation at the point of initial access. Furthermore, because the vulnerability is triggered by processing a maliciously crafted file, it also relates to CWE-20: Improper Input Validation and potentially CWE-134: Use of Externally-Controlled Format String if format strings are involved in the memory interpretation, though the primary mechanism here is the boundary violation itself. The fact that this issue affects multiple operating systems including iOS, iPadOS, macOS, tvOS, visionOS, and watchOS indicates a shared underlying codebase or library responsible for font rendering across Apple's ecosystem, suggesting a systemic architectural weakness rather than an isolated incident in a single application.
Mitigation strategies primarily rely on the deployment of the software updates provided by the vendor, which include iOS 27, iPadOS 27, macOS Golden Gate 27, tvOS 27, visionOS 27, and watchOS 27. These patches incorporate the necessary bounds checking logic to prevent the out-of-bounds access from occurring during font processing operations. For organizations managing large fleets of devices, it is critical to prioritize these updates due to the widespread nature of the vulnerability across all major platforms. In addition to patching, defense-in-depth measures such as enabling sandboxing for applications that handle untrusted fonts can limit the blast radius if a zero-day exploit were present in older versions. Security teams should also monitor for anomalous memory access patterns or unexpected data exfiltration attempts, although detection of this specific vulnerability may be challenging without specialized endpoint security tools capable of monitoring low-level system calls and memory integrity violations. Regular auditing of third-party libraries used for font rendering can further reduce the attack surface by ensuring that only validated and secure components are utilized within critical system processes.