CVE-2025-43398 is a vulnerability identified in Apple macOS and several other Apple operating systems such as iOS, iPadOS, tvOS, watchOS, and visionOS. The root cause is improper memory handling that allows a local application with limited privileges (low privilege) to cause unexpected system termination, effectively a denial-of-service condition. The vulnerability is classified under CWE-119, which relates to improper restriction of operations within the bounds of a memory buffer, indicating a memory corruption issue. The CVSS v3.1 base score is 5.5 (medium severity), with an attack vector of local (AV:L), low attack complexity (AC:L), requiring privileges (PR:L), no user interaction (UI:N), and impacting availability only (A:H) without affecting confidentiality or integrity. This means an attacker must have local access and some privileges on the device but does not need to trick the user to exploit the flaw. The vulnerability affects unspecified versions of the Apple operating systems but has been fixed in recent updates including macOS Tahoe 26.1, macOS Sequoia 15.7.2, macOS Sonoma 14.8.2, iOS 26.1, iOS 18.7.2, and corresponding versions of other Apple OSes. The fix involves improved memory handling to prevent the crash condition. No public exploits or active exploitation campaigns are known at this time. The vulnerability could be leveraged by malicious local apps or attackers who gain limited access to cause system crashes, potentially disrupting operations or causing denial of service on affected Apple devices.

For European organizations, the primary impact of CVE-2025-43398 is the risk of denial of service on Apple devices running vulnerable OS versions. This could disrupt business operations, especially in environments relying on macOS or other Apple OS devices for critical workflows. Although the vulnerability does not compromise confidentiality or integrity, unexpected system terminations can lead to data loss, reduced productivity, and operational downtime. Organizations with a high density of Apple devices, such as creative industries, software development firms, and enterprises using Apple hardware for endpoint computing, are particularly vulnerable. Additionally, sectors with stringent availability requirements like finance, healthcare, and government could face operational risks if attackers exploit this flaw to cause repeated crashes. The lack of known exploits reduces immediate risk, but the medium severity and ease of local exploitation mean that insider threats or malware with local access could leverage this vulnerability. The broad range of affected Apple OS versions increases the attack surface across multiple device types including desktops, laptops, tablets, and wearables.

1. Apply the latest Apple OS updates immediately: Upgrade all Apple devices to the patched versions macOS Tahoe 26.1, macOS Sequoia 15.7.2, macOS Sonoma 14.8.2, iOS 26.1, iOS 18.7.2, and corresponding versions for other Apple OSes to ensure the vulnerability is remediated. 2. Restrict app installations to trusted sources only, such as the Apple App Store, and enforce strict application whitelisting policies to prevent untrusted or malicious apps from running locally. 3. Implement endpoint protection solutions that monitor for abnormal app behavior or repeated crashes indicative of exploitation attempts. 4. Limit local user privileges on Apple devices to the minimum necessary, reducing the likelihood that a low-privilege app can exploit the vulnerability. 5. Conduct regular audits of installed applications and remove unnecessary or suspicious software that could be leveraged for local attacks. 6. Educate users about the risks of installing unauthorized software and the importance of applying system updates promptly. 7. For critical environments, consider additional monitoring for system stability and automated alerts on unexpected system terminations to enable rapid incident response.