CVE-2025-43435 is a vulnerability identified in Apple Safari that arises from improper memory handling when processing maliciously crafted web content. This vulnerability is categorized under CWE-119, indicating a buffer-related memory safety issue. When exploited, it causes an unexpected process crash, leading to a denial of service (DoS) condition within the Safari browser process. The issue affects multiple Apple operating systems and devices, including tvOS, watchOS, macOS (Tahoe), iOS, iPadOS, and visionOS, specifically versions prior to 26.1 and iOS/iPadOS 18.7.2. The vulnerability requires no privileges or authentication but does require user interaction, such as visiting a maliciously crafted web page. The CVSS v3.1 score is 4.3 (medium severity), reflecting the limited impact on confidentiality and integrity but a tangible impact on availability. Apple addressed this vulnerability by improving memory handling in the affected components, releasing patches across their platforms. There are no known exploits in the wild at the time of publication, but the nature of the flaw means attackers could cause denial of service by crashing Safari processes, potentially disrupting user activities or automated systems relying on Safari. The vulnerability’s broad platform impact necessitates timely patching to mitigate potential service interruptions and reduce attack surface.

For European organizations, the primary impact of CVE-2025-43435 is the potential for denial of service through unexpected crashes of the Safari browser. This can disrupt business operations, especially for organizations relying heavily on Apple devices for web-based applications, remote work, or customer-facing services. While the vulnerability does not compromise data confidentiality or integrity, repeated crashes could lead to productivity loss, user frustration, and potential indirect impacts such as delayed transactions or communications. Organizations in sectors like finance, healthcare, and government that utilize Apple ecosystems extensively may experience operational disruptions. Additionally, automated systems or kiosks using Safari for web content display could be affected, causing service outages. The absence of known exploits reduces immediate risk, but the medium severity rating and ease of triggering the crash via crafted web content mean attackers could weaponize this vulnerability for targeted denial of service attacks. European organizations should consider the risk in the context of their Apple device usage and exposure to untrusted web content.

1. Immediate deployment of Apple’s security updates: Upgrade all affected devices to tvOS 26.1, watchOS 26.1, macOS Tahoe 26.1, iOS 26.1, iPadOS 26.1, Safari 26.1, iOS 18.7.2, and iPadOS 18.7.2 or later to ensure the vulnerability is patched. 2. Implement network-level filtering to restrict access to known malicious or untrusted websites, reducing exposure to crafted web content. 3. Use web content filtering and DNS security solutions to block suspicious domains and URLs that could host exploit code. 4. Educate users about the risks of visiting untrusted websites and encourage cautious browsing behavior, especially on Apple devices. 5. Monitor Safari browser crash logs and system event logs for unusual patterns that may indicate exploitation attempts. 6. For critical environments, consider isolating Apple devices or limiting their use for sensitive operations until patched. 7. Employ endpoint detection and response (EDR) solutions capable of detecting abnormal process terminations or memory corruption indicators. 8. Regularly review and update incident response plans to include scenarios involving browser-based denial of service attacks.