CVE-2025-43518 is a logic vulnerability in the spellcheck API of Apple operating systems including macOS (Sonoma 14.8.3, Tahoe 26.2, Sequoia 15.7.3), watchOS 26.2, iOS 26.2, and iPadOS 26.2. The flaw allows an application with limited privileges to bypass intended access controls and inappropriately access files via the spellcheck API. This vulnerability stems from insufficient validation or authorization checks within the API's logic, categorized under CWE-284 (Improper Access Control). Exploitation requires local access with low privileges and does not require user interaction, limiting the attack vector to local or insider threats. The CVSS v3.1 score is 3.3 (low severity), reflecting limited confidentiality impact and no integrity or availability impact. Apple addressed the issue by implementing improved access checks in the spellcheck API in the specified OS versions. No public exploits have been reported, indicating low current risk but potential for future abuse if unpatched. The vulnerability primarily threatens confidentiality by enabling unauthorized file access, which could lead to data leakage or exposure of sensitive information. The patch availability across multiple Apple OS versions underscores the importance of updating all affected devices to mitigate the risk.

For European organizations, the primary impact is unauthorized access to files on Apple devices, potentially leading to exposure of sensitive or confidential data. While the vulnerability does not allow modification or deletion of files, unauthorized read access can compromise privacy and intellectual property. Organizations with employees or infrastructure relying on Apple macOS, iOS, or related systems are at risk, especially if devices are shared or used in sensitive environments. The requirement for local access and limited privileges reduces the likelihood of remote exploitation but raises concerns about insider threats or malware that gains initial foothold on devices. In sectors such as finance, healthcare, and government, where data confidentiality is paramount, this vulnerability could facilitate data breaches or espionage. The absence of known exploits currently lowers immediate risk, but delayed patching could increase exposure over time. Additionally, organizations using Apple devices in hybrid environments may face challenges ensuring all endpoints are updated promptly, increasing the attack surface.

1. Deploy the latest Apple OS updates immediately: macOS Sonoma 14.8.3, Tahoe 26.2, Sequoia 15.7.3, watchOS 26.2, iOS 26.2, and iPadOS 26.2 contain the fix and should be applied across all devices. 2. Enforce strict app permission policies: Limit which applications can access the spellcheck API or sensitive file system areas, using Apple’s built-in privacy controls and Mobile Device Management (MDM) solutions. 3. Monitor for unusual local activity: Implement endpoint detection and response (EDR) tools to detect anomalous file access patterns or unauthorized API usage on Apple devices. 4. Educate users about insider threats and local access risks, emphasizing the importance of device security and reporting suspicious behavior. 5. Restrict physical and remote access to Apple devices, ensuring that only authorized personnel can log in locally. 6. Conduct regular audits of installed applications to identify and remove unnecessary or potentially risky software that could exploit this vulnerability. 7. Integrate patch management into organizational security policies to ensure timely updates across all Apple platforms.