CVE-2025-43235 is a medium-severity vulnerability affecting Apple macOS, specifically addressed in macOS Sequoia 15.6. The vulnerability arises from improper memory handling that allows a malicious application to trigger a denial-of-service (DoS) condition. The underlying weakness is categorized under CWE-400, which relates to uncontrolled resource consumption. An attacker can exploit this vulnerability by running a specially crafted app that, through triggering excessive resource usage or memory exhaustion, causes the system or affected process to become unresponsive or crash. The CVSS v3.1 base score is 5.5, reflecting a medium severity level, with an attack vector of local (AV:L), low attack complexity (AC:L), no privileges required (PR:N), but requiring user interaction (UI:R). The impact is limited to availability (A:H), with no confidentiality or integrity impact. No known exploits are currently in the wild, and the vulnerability was publicly disclosed in July 2025. The fix involves improved memory handling implemented in the latest macOS Sequoia 15.6 update, though affected versions are unspecified. This vulnerability does not require elevated privileges but does require the user to run a malicious app, which could be delivered via social engineering or other means. Given the local attack vector, exploitation is limited to users who can execute code on the target system.

For European organizations, the primary impact of CVE-2025-43235 is the potential disruption of macOS-based systems through denial-of-service attacks. This could affect end-user productivity, especially in environments where macOS devices are integral to operations such as creative industries, software development, and executive workstations. While the vulnerability does not compromise data confidentiality or integrity, repeated or targeted DoS attacks could degrade service availability, cause system instability, and increase support and recovery costs. Organizations relying on macOS for critical functions may experience operational interruptions. Additionally, if attackers leverage social engineering to trick users into running malicious apps, this could lead to broader security concerns. However, since exploitation requires local access and user interaction, the risk is somewhat mitigated in tightly controlled enterprise environments with strict application controls and user awareness training.

To mitigate CVE-2025-43235, European organizations should prioritize updating all macOS devices to macOS Sequoia 15.6 or later, where the vulnerability is fixed with improved memory handling. Implementing application whitelisting and restricting the execution of unauthorized or untrusted applications can reduce the risk of malicious app execution. User education campaigns should emphasize the dangers of running unknown or suspicious applications, especially those received via email or external media. Endpoint protection solutions with behavioral detection can help identify and block attempts to exploit resource exhaustion. Network segmentation and limiting local user privileges can further reduce the attack surface. Regular monitoring of system performance and logs may help detect early signs of attempted DoS conditions. Finally, organizations should maintain an inventory of macOS devices and ensure patch management processes are robust and timely.