CVE-2025-43186 is a critical memory handling vulnerability in Apple’s macOS and associated operating systems (iOS, iPadOS, watchOS, tvOS, visionOS). The vulnerability arises from improper bounds checking during file parsing, classified as CWE-119, which can lead to unexpected application termination or potentially arbitrary code execution. The flaw does not require any privileges or user interaction to be exploited, making it remotely exploitable over the network if an attacker can deliver a maliciously crafted file to the target system. The vulnerability affects multiple Apple OS versions, including macOS Sequoia 15.6, Sonoma 14.7.7, Ventura 13.7.7, and iOS/iPadOS/watchOS/tvOS/visionOS 18.6. Apple addressed the issue by improving memory handling in these updates. The CVSS v3.1 base score is 9.8, reflecting the critical nature of the vulnerability with high impact on confidentiality, integrity, and availability. No public exploits are known yet, but the vulnerability’s characteristics suggest it could be weaponized for denial of service or remote code execution attacks. Organizations relying on Apple devices should prioritize patching and monitor for suspicious file parsing activities to mitigate risk.

The vulnerability allows attackers to cause unexpected application termination or potentially execute arbitrary code remotely without authentication or user interaction. This can lead to denial of service, loss of data confidentiality and integrity, and compromise of system availability. For European organizations, especially those in finance, government, healthcare, and critical infrastructure sectors that rely heavily on Apple devices, this vulnerability could disrupt operations, lead to data breaches, or enable further lateral movement within networks. The broad range of affected Apple operating systems increases the attack surface. If exploited, attackers could gain control over affected systems, exfiltrate sensitive data, or disrupt essential services, causing significant operational and reputational damage.

1. Immediately apply the security updates released by Apple for macOS Sequoia 15.6, Sonoma 14.7.7, Ventura 13.7.7, and iOS/iPadOS/watchOS/tvOS/visionOS 18.6 or later. 2. Implement strict file handling policies to restrict the receipt and opening of untrusted or unsolicited files, especially from external sources. 3. Employ network-level protections such as intrusion detection/prevention systems (IDS/IPS) to detect anomalous file parsing or exploitation attempts. 4. Conduct regular endpoint monitoring and logging to identify unusual application crashes or suspicious activities related to file parsing. 5. Educate users on the risks of opening unknown files and encourage reporting of abnormal system behavior. 6. For high-risk environments, consider deploying application whitelisting and sandboxing techniques to limit the impact of potential exploitation. 7. Maintain an up-to-date asset inventory to ensure all Apple devices are identified and patched promptly.